bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tonic Seizures: Their Significance for Lateralization and Frequency in Different Focal Epileptic Syndromes
Authors: Werhahn Konrad J. , Noachtar Soheyl , Arnold Stephan , Pfänder Mona , Henkel Anja , Winkler Peter A. , Lüders Hans O. 
Published: August 2005

Summary: Purpose: To determine whether the clinical features of tonic seizures (TSZ) are useful for lateralization of epileptic syndromes and the differential diagnosis of focal epileptic syndromes. Methods: From a group of 481 patients, 123 patients with TSZ (44 females; mean age, 22.9 years; mean age at onset, 7 years; mean duration of epilepsy, 16 years) were selected. A total of 1595 epileptic seizures, documented during video‐electroencephalographic monitoring, were analyzed. Patients who had had surgery for epilepsy previously were excluded. Seizures were classified using a semiological seizure classification. Epilepsy syndromes were classified using all test data (electroencephalography, magnetic resonance imaging, computed tomography, positron emission tomography, and single‐photon emission tomography). Data were compared using χ2 analysis or the Fisher exact test. Results: More patients with TSZ had extratemporal than temporal lobe epilepsies (79% vs. 1.7%; p < 0.0001) among those with an epilepsy localized to one lobe (n = 306). In the 123 patients, TSZ were part of 170 different seizure evolutions. Seizure evolutions began with TSZ as the first seizure type more often in patients with frontal lobe epilepsy (FLE) compared with patients with parieto‐occipital lobe epilepsy (POLE) (40% in POLE vs. 67% in FLE; p < 0.05). In contrast, TSZ in POLE were more likely to be preceded by auras (50% in POLE vs. 26% in FLE; p < 0.05). TSZ were bilateral in 129 (76%) and unilateral in 41 (24%) seizure evolutions. Unilateral TSZ correctly lateralized the epilepsy syndrome to the contra‐lateral hemisphere. Conclusion: Analysis of seizure semiology and evolution in patients with TSZ is helpful for differentiating between focal epilepsies of temporal, frontal, and parieto‐occipital origin. Unilateral TSZ provide useful information for the lateralization of the epileptic syndrome.
Multicenter Double‐Blind, Randomized, Placebo‐Controlled Trial of Levetiracetam as Add‐On Therapy in Patients with Refractory Partial Seizures
Authors: Shorvon Simon D. , Löwenthal Armand , Janz Dieter , Bielen Edith , Loiseau Pierre ,   for the European Levetiracetam Study Group
Published: August 2005

Summary: Purpose: To evaluate the efficacy and tolerability of levetiracetam (LEV, Keppra) as add‐on therapy in patients with refractory partial seizures. Methods: In this European multicenter, double‐blind, randomized, placebo‐controlled trial, LEV (500 or 1,000 mg twice daily) was compared with placebo as add‐on therapy in 324 patients with uncontrolled simple or complex partial seizures, or both, with or without secondary generalization. After enrollment, three parallel groups were assessed during a baseline period of 8 or 12 weeks, followed by a 4‐week titration interval and a 12‐week evaluation period. Results: LEV significantly decreased partial seizure frequency compared with placebo. A reduction in seizure frequency of 50% occurred in 22.8% of patients in the 1,000‐mg group and 31.6% of patients in the 2,000‐mg group, compared with 10.4% of patients in the placebo group. Administration of LEV did not affect plasma concentrations of concomitant an‐tiepileptic drugs or alter vital signs or laboratory parameters. No significant difference in the incidence of adverse events was observed between treatment groups (70.8% for the 1,000‐mg group and 75.5% for the 2,000‐mg group), or between the LEV and placebo groups (73.2% for placebo group). The most commonly reported adverse effects in the LEV group were asthenia, headache, and somnolence. Conclusions: The antiepileptic efficacy and tolerability of LEV (1,000 mg/d and 2,000 mg/d, administered in two divided doses) as add‐on therapy was established in patients with refractory partial seizures in this clinical study.
Relationship of Seizure Frequency to Hippocampus Volume and Metabolism in Temporal Lobe Epilepsy
Authors: Spanaki M. V. , Kopylev L. , Liow K. , DeCarli C. , Fazilat S. , Gaillard W. D. , Theodore W. H. 
Published: August 2005

Summary: Purpose: To examine the relationship between frequency of complex partial (CPS) and secondarily generalized tonic‐clonic seizures (sGTCS) on hippocampal volume (HV) and temporal lobe metabolism. Methods: We performed volumetric magnetic resonance imaging (MRI) and positron emission tomography with 18fluorodeoxyglucose (18FDG‐PET) in 32 patients with epilepsy. Temporal lobe foci were localized by ictal video‐EEG. Results: We did not find any association between CPS frequency or lifetime number of sGTCS and HV or metabolism ipsilateral to electroencephalographic focus. Conclusion: The progress of metabolic or pathologic abnormalities of temporal lobe epilepsy may not be altered by adequate seizure control. The presence of an epileptic focus might be associated with progressive neuronal injury even in clinically well‐controlled patients.
Epilepsy Can Be Diagnosed When the First Two Seizures Occur on the Same Day
Authors: Camfield Peter , Camfield Carol 
Published: August 2005

Summary: Purpose: Experts have suggested that when the first two (or more) unprovoked seizures occur on the same day, they should be considered as a single event and the diagnosis of epilepsy await a further seizure. We have studied the subsequent clinical course of children with their first two seizures on the same day (“same day” group) compared with children with their first two seizures separated by more than one day (“different day” group). Method: The Nova Scotia childhood epilepsy database documented all newly diagnosed children with epilepsy from 1977 to 1985 with follow‐up in 1990 and 1991. Epilepsy was defined as two or more unprovoked seizures regardless of the interval between seizures provided that consciousness fully returned between seizures. All patients had their first seizure between the ages of 1 month and 16 years. Seizure types were restricted to partial, generalized tonic‐clonic, and partial with secondary generalization. Results: Of the 490 children with partial or generalized tonic‐clonic seizures and follow‐up of more than 2 years, 70 had their first two or more seizures on the same day and 420 had their first two seizures on different days. Eighty percent (56 of 70) of the “same day” group subsequently had one or more further seizures with (n = 14) or without (n = 42) medication; 80.9% (340 of 420) of the “different day” group had one or more further seizures with (n = 115) or without (n = 225) medication. Seizure types were nearly identical. Cause was the same (except for fewer idiopathic “genetic” cases in the “same day” group: 1 of 70 vs. 42 of 420; p = 0.02). Rates of mental handicap and previous febrile seizures were the same. Children in the “same day” group were younger on average (60 vs. 84 months; p = 0.001) and were somewhat more likely to have neurological impairment. Outcome after 7 years average follow‐up was the same: 58% of the “same day” group and 56% of the “different day” group were in remission. Conclusion: If two or more unprovoked seizures (with normal consciousness between) occur on the same day, the child appears to have epilepsy and will have a clinical course identical to that of the child with a longer time interval between the first two seizures.
Photogenic Partial Seizures
Authors: Hennessy Michael J. , Binnie Colin D. 
Published: August 2005

Summary: Purpose: To establish the incidence and symptoms of partial seizures in a cohort of patients investigated on account of known sensitivity to intermittent photic stimulation and/or precipitation of seizures by environmental visual stimuli such as television (TV) screens or computer monitors. Methods: We report 43 consecutive patients with epilepsy, who had exhibited a significant EEG photoparoxysmal response or who had seizures precipitated by environmental visual stimuli and underwent detailed assessment of their photosensitivity in the EEG laboratory, during which all were questioned concerning their ictal symptoms. Results: All patients were considered on clinical grounds to have an idiopathic epilepsy syndrome. Twenty‐eight (65%) patients reported visually precipitated attacks occurring initially with maintained consciousness, in some instances evolving to a period of confusion or to a secondarily generalized seizure. Visual symptoms were most commonly reported and included positive symptoms such as coloured circles or spots, but also blindness and subjective symptoms such as “eyes going funny”Other symptoms described included nonspecific cephalic sensations, deja‐vu, auditory hallucinations, nausea, and vomiting. No patient reported any clear spontaneous partial seizures, and there were no grounds for supposing that any had partial epilepsy excepting the ictal phenomenology of some or all of the visually induced attacks. Conclusions: These findings provide clinical support for the physiological studies that indicate that the trigger mechanism for human photosensitivity involves binocularly innervated cells located in the visual cortex. Thus the visual cortex is the seat of the primary epileptogenic process, and the photically triggered discharges and seizures may be regarded as partial with secondary generalization.
Synaptic Properties of Neocortical Neurons in Epileptic Mice Lacking the Otx1 Gene
Authors: Avanzini G. , Spreafico R. , Cipelletti B. , Sancini G. , Frassoni C. , Franceschetti S. , Lavazza T. , Panzica F. , Acampora D. , Simeone A. 
Published: August 2005

Summary: Purpose: The murine homeobox‐containing Otx gene is required for correct nervous system and sense organ development. Otx1−/− mice obtained by replacing Otx with the lac Z gene show developmental abnormalities of the cerebellum, mesencephalon, and cerebral cortex associated with spontaneous epileptic seizures (1). The epileptogenic mechanisms accounting for these seizures were investigated by means of electrophysiological recordings made from neocortical slices. Methods: The 400‐μm slices were prepared from the somato‐sensory cortex of Otx1−/− and Otx1+/+ mice, and the current clamp intracellular recordings were obtained from layer V pyramidal neurons by means of pipettes containing K+ acetate 1·5 mol/L and biocytin 2% (pH 7·3). Results: Synaptic responses could be evoked in the neocortical pyramidal neurons by electrically stimulating the underlying white matter. μ‐Aminobutyric acid A/B—mediated inhibitory postsynaptic potentials were more pronounced in the Otx1−/− than in the control pyramidal neurons from the earliest postnatal period; multisynaptic excitatory postsynaptic potentials were significantly more expressed in the Otx1−/− mice also at the end of the first postnatal month, when they were only rarely encountered in controls. Conclusion: Excessive excitatory amino acid—mediated synaptic driving may lead to a hyperexcitable condition that is responsible for the epileptic manifestations occurring in Otx1−/− mice. This excess of excitation is not counteracted by well‐developed γ‐aminobutyric acid activity, which seems to be involved in the synchronization of cell discharges. Our ongoing and more extensive comparative analysis of the mutants and controls should help to clarify the way in which the putative rearrangement taking place in Otx1−/− neocortex may lead to the excitatory hyperinnervation of layer V pyramidal neurons.
Concentration—Effect Studies with Topiramate on Selected Enzymes and Intermediates of the GABA Shunt
Authors: Sills Graeme J. , Leach John P. , Kilpatrick W. Stewart , Fraser Caroline M. , Thompson George G. , Brodie Martin J. 
Published: August 2005

Summary: Purpose: Topiramate (TPM) is a new antiepileptic agent with a multifactorial mechanism of action. The drug potentiates responses to γ‐aminobutyric acid (GABA) at the GABAA receptor and has inhibitory effects on neuronal sodium channels, the AMPA/kainate subtype of glutamate receptor, and carbonic anhydrase. Recent evidence has, however, suggested that the drug also increases brain GABA concentrations in humans. These studies were designed to investigate the neurochemical basis of this observation. Methods: Adult male mice were randomised into two groups and administered TPM (0–1,000 mg/kg) intraperitoneally either as a single dose or daily for 8 days. At 4 h after the final dose, brain tissues were analysed for concentrations of GABA, glutamate, and glutamine and for the activities of GABA‐transaminase and glutamic acid decarboxylase. TPM levels in brain also were determined. Results: Single‐dose and repeated TPM treatments were without effect on all of the parameters investigated, although the drug was detectable in the brain at doses of 10 mg/kg. Conclusions: These results contradict the reported increase in brain GABA concentrations with TPM. More detailed studies are required to determine the basis of this clinical observation and the extent to which it contributes to the antiepileptic activity of the drug.
Clifford Algebra Exponentials and Planar Linkage Synthesis Equations
Authors: Perez Alba , McCarthy J. Michael 
Published: August 2005

Abstract
This paper uses the exponential defined on a Clifford algebra of planar projective space to show that the “standard-form” design equations used for planar linkage synthesis are obtained directly from the relative kinematics equations of the chain. The relative kinematics equations of a serial chain appear in the matrix exponential formulation of the kinematics equations for a robot. We show that formulating these same equations using a Clifford algebra yields design equations that include the joint variables in a way that is convenient for algebraic manipulation. The result is a single formulation that yields the design equations for planar 2R dyads, 3R triads, and nR single degree-of-freedom coupled serial chains and facilitates the algebraic solution of these equations including the inverse kinematics of the chain. These results link the basic equations of planar linkage design to standard techniques in robotics.
Methanol-Dependent Gene Expression Demonstrates that Methyl-Coenzyme M Reductase Is Essential in
Methanosarcina acetivorans
C2A and Allows Isolation of Mutants with Defects in Regulation of the Methanol Utilization Pathway
Authors: Rother Michael , Boccazzi Paolo , Bose Arpita , Pritchett Matthew A. , Metcalf W. W. 
Published: August 2005

ABSTRACT

Methanosarcina acetivorans
C2A is able to convert several substrates to methane via at least four distinct methanogenic pathways. A common step in each of these pathways is the reduction of methyl-coenzyme M (CoM) to methane catalyzed by methyl-CoM reductase (MCR). Because this enzyme is used in each of the known pathways, the
mcrBDCGA
operon, which encodes MCR, is expected to be essential. To validate this prediction, a system for conditional gene inactivation was developed. A heterologous copy of the
mcrBDCGA
operon was placed under the control of the highly regulated
mtaC1
promoter, which directs the expression of genes involved in methanol utilization, and recombined onto the
M. acetivorans
chromosome. This allowed for disruption of the endogenous
mcr
operon in the presence of methanol. Because the
PmtaC1
promoter is transcribed only during growth on methanol,
mcrBDCGA
was rendered methanol dependent and the strain was unable to grow in trimethylamine media, strongly suggesting that
mcrBDCGA
is essential. Upon prolonged incubation, suppressed mutants which expressed
mcrBDCGA
constitutively could be selected. Expression analysis of
PmtaC1
::
uidA
gene fusions in several isolated suppressed mutants suggests that they carry
trans
-active mutations leading to deregulation of all genes under control of this promoter. Subsequently, proteome analysis of one such suppressed mutant revealed that all known proteins derived from
mtaC1
promoter-dependent expression were constitutively expressed in this mutant. This genetic system can therefore be employed for the testing of essential genes and for the identification of genes under a common regulatory mechanism by making regulatory mutations phenotypically selectable.
Upstream Migration ofXylella fastidiosavia Pilus-Driven Twitching Motility
Authors: Meng Yizhi , Li Yaxin , Galvani Cheryl D. , Hao Guixia , Turner James N. , Burr Thomas J. , Hoch H. C. 
Published: August 2005

ABSTRACTXylella fastidiosais a xylem-limited nonflagellated bacterium that causes economically important diseases of plants by developing biofilms that block xylem sap flow. How the bacterium is translocated downward in the host plant's vascular system against the direction of the transpiration stream has long been a puzzling phenomenon. Using microfabricated chambers designed to mimic some of the features of xylem vessels, we discovered thatX. fastidiosamigrates via type IV-pilus-mediated twitching motility at speeds up to 5 μm min−1against a rapidly flowing medium (20,000 μm min−1). Electron microscopy revealed that there are two length classes of pili, long type IV pili (1.0 to 5.8 μm) and short type I pili (0.4 to 1.0 μm). We further demonstrated that two knockout mutants (pilBandpilQmutants) that are deficient in type IV pili do not twitch and are inhibited from colonizing upstream vascular regions in planta. In addition, mutants with insertions inpilBorpilQ(possessing type I pili only) express enhanced biofilm formation, whereas a mutant with an insertion infimA(possessing only type IV pili) is biofilm deficient.
The
agr
Radiation: an Early Event in the Evolution of Staphylococci
Authors: Wright Jesse S. , Traber Katrina E. , Corrigan Rebecca , Benson Sarah A. , Musser James M. , Novick Richard P. 
Published: August 2005

ABSTRACT

agr
is a global regulatory system in the staphylococci, operating by a classical two-component signaling module and controlling the expression of most of the genes encoding extracellular virulence factors. As it is autoinduced by a peptide, encoded within the locus, that is the ligand for the signal receptor, it is a sensor of population density or a quorum sensor and is the only known quorum-sensing system in the genus.
agr
is conserved throughout the staphylococci but has diverged along lines that appear to parallel speciation and subspeciation within the genus. This divergence has given rise to a novel type of interstrain and interspecies cross-inhibition that represents a fundamental aspect of the organism's biology and may be a predominant feature of the evolutionary forces that have driven it. We present evidence, using a newly developed, luciferase-based
agr
typing scheme, that the evolutionary divergence of the
agr
system was an early event in the evolution of the staphylococci and long preceded the development of the nucleotide polymorphisms presently used for genotyping. These polymorphisms developed, for the most part, within different
agr
groups; mobile genetic elements appear also to have diffused recently and, with a few notable exceptions, have come to reside largely indiscriminately within the several
agr
groups.
FliG Subunit Arrangement in the Flagellar Rotor Probed by Targeted Cross-Linking
Authors: Lowder Bryan J. , Duyvesteyn Mark D. , Blair David F. 
Published: August 2005

ABSTRACT

FliG is a component of the switch complex on the rotor of the bacterial flagellum. Each flagellar motor contains about 25 FliG molecules. The protein of
Escherichia coli
has 331 amino acid residues and comprises at least two discrete domains. A C-terminal domain of about 100 residues functions in rotation and includes charged residues that interact with the stator protein MotA. Other parts of the FliG protein are essential for flagellar assembly and interact with the MS ring protein FliF and the switch complex protein FliM. The crystal structure of the middle and C-terminal parts of FliG shows two globular domains joined by an α-helix and a short extended segment that contains two well-conserved glycine residues. Here, we describe targeted cross-linking studies of FliG that reveal features of its organization in the flagellum. Cys residues were introduced at various positions, singly or in pairs, and cross-linking by a maleimide or disulfide-inducing oxidant was examined. FliG molecules with pairs of Cys residues at certain positions in the middle domain formed disulfide-linked dimers and larger multimers with a high yield, showing that the middle domains of adjacent subunits are in fairly close proximity and putting constraints on the relative orientation of the domains. Certain proteins with single Cys replacements in the C-terminal domain formed dimers with moderate yields but not larger multimers. On the basis of the cross-linking results and the data available from mutational and electron microscopic studies, we propose a model for the organization of FliG subunits in the flagellum.
SarA Positively Controls Bap-Dependent Biofilm Formation in
Staphylococcus aureus
Authors: Trotonda María Pilar , Manna Adhar C. , Cheung Ambrose L. , Lasa Iñigo , Penadés José R. 
Published: August 2005

ABSTRACT

The biofilm-associated protein Bap is a staphylococcal surface protein involved in biofilm formation. We investigated the influence of the global regulatory locus
sarA
on
bap
expression and Bap-dependent biofilm formation in three unrelated
Staphylococcus aureus
strains. The results showed that Bap-dependent biofilm formation was diminished in the
sarA
mutants by an
agr
-independent mechanism. Complementation studies using a
sarA
clone confirmed that the defect in biofilm formation was due to the
sarA
mutation. As expected, the diminished capacity to form biofilms in the
sarA
mutants correlated with the decreased presence of Bap in the bacterial surface. Using transcriptional fusion and Northern analysis data, we demonstrated that the
sarA
gene product acts as an activator of
bap
expression. Finally, the
bap
promoter was characterized and the transcriptional start point was mapped by the rapid amplification of cDNA ends technique. As expected, we showed that purified SarA protein binds specifically to the
bap
promoter, as determined by gel shift and DNase I footprinting assays. Based on the previous studies of others as well as our work demonstrating the role for SarA in
icaADBC
and
bap
expression (J. Valle, A. Toledo-Arana, C. Berasain, J. M. Ghigo, B. Amorena, J. R. Penades, and I. Lasa, Mol. Microbiol. 48:1075-1087), we propose that SarA is an essential regulator controlling biofilm formation in
S. aureus
.
The Large First Periplasmic Loop of SecD and SecF Plays an Important Role in SecDF Functioning
Authors: Nouwen Nico , Piwowarek Magdalena , Berrelkamp Greetje , Driessen Arnold J. M. 
Published: August 2005

ABSTRACT
A remarkable feature of proteins of the SecD and SecF family involved in protein translocation is that they possess a very large first periplasmic domain. Here we report that this large first periplasmic domain is not required for the SecD-SecF interaction but that it is important for catalyzing protein translocation.
On popular participation in a culture of patronage; patrons and grassroots organization in a sites and services project in Hyderabad, Pakistan
Authors: van der Linden Jan 
Published: August 2005

This paper begins by discussing the ways in which patronage inhibits housing solutions for low-income groups and the conditions under which it has greatest scope for operating. There follows a discussion of what factors diminish the power of patronage within the context of a government-run site and service programme in Hyderabad (Pakistan). Here, reducing scarcity (in this case affordable land sites) and the distance between people and government were important in reducing (although not removing) the role of patrons. The paper ends with some suggestions as to how the role of patrons can be reduced in government projects - and how low-income households' direct access to land and basic services without the involvement of a patron are among the best forms of “participation”. “If you live in the river, it is better to stay friends with the crocodile” (Pakistani proverb).