bluuebunny/crossref_metadata_2025 huggingface dataset:
Children with Epilepsy: Why Can't They Pay Attention?
Authors: Bergen Donna C.
Published: December 2008

The Frequency, Complications and Aetiology of ADHD in New Onset Paediatric Epilepsy. Hermann B, Jones J, Dabbs K, Allen CA, Sheth R, Fine J, McMillan A, Seidenberg M. Brain 2007;130(Pt 12):3135–3148. Recent studies suggest that Attention Deficit Hyperactivity Disorder (ADHD) is a common comorbid condition in childhood epilepsy, but little is known regarding the nature, frequency and timing of associated neurobehavioural/cognitive complications or the underlying aetiology of ADHD in epilepsy. This investigation examined: (i) the prevalence of ADHD and its subtypes; (ii) the association of ADHD with abnormalities in academic, neuropsychological, behavioural and psychiatric status and (iii) the aetiology of ADHD in paediatric epilepsy. Seventy-five children (age 8–18) with new/recent onset idiopathic epilepsy and 62 healthy controls underwent structured interview (K-SADS) to identify the presence and type of DSM-IV defined ADHD, neuropsychological assessment, quantitative MR volumetrics, characterization of parent observed executive function, review of academic/educational progress and assessment of risk factors during gestation and delivery. The results indicate that ADHD is significantly more prevalent in new onset epilepsy than healthy controls (31% vs 6%), characterized predominantly by the inattentive variant, with onset antedating the diagnosis of epilepsy in the majority of children. ADHD in childhood epilepsy is associated with significantly increased rates of school based remedial services for academic underachievement, neuropsychological consequences with prominent differences in executive function, and parent-reported dysexecutive behaviours. ADHD in paediatric epilepsy is neither associated with demographic or clinical epilepsy characteristics nor potential risk factors during gestation and birth. Quantitative MRI demonstrates that ADHD in epilepsy is associated with significantly increased gray matter in distributed regions of the frontal lobe and significantly smaller brainstem volume. Overall, ADHD is a prevalent comorbidity of new onset idiopathic epilepsy associated with a diversity of salient educational, cognitive, behavioural and social complications that antedate epilepsy onset in a significant proportion of cases, and appear related to neurodevelopmental abnormalities in brain structure.
Some Long Awaited Answers regarding Seizures during Pregnancy
Authors: Ben-Menachem Elinor
Published: December 2008

Seizure Control in Antiepileptic Drug-Treated Pregnancy. Vajda FJ, Hitchcock A, Graham J, O'Brien T, Lander C, Eadie M. Epilepsia 2008;49(1):172–176. This brief report covers an analysis of 7 years outcome data from the Australian Register of Antiepileptic Drugs in Pregnancy. In studying the control of antiepileptic drug-treated epileptic seizures during pregnancy, it was found that pregnancy had little influence on antiepileptic drug-treated epileptic seizure disorders. Seizures during pregnancy occurred in 49.7% of 841 antiepileptic drug (AED) treated pregnancies in women with epilepsy. Epilepsies that were active in the year before pregnancy tended to increase the risk of intrapartum and postpartum seizures. The risk of seizures during pregnancy was 50–70% less if the prepregnancy year was seizure-free, and decreased relatively little more with longer periods of prepregnancy seizure control. Once there had been 1 year's freedom from seizures there seemed relatively little further advantage in deferring pregnancy to avoid seizures returning while pregnant.
Molecular Pathology of Genetic Epilepsies Associated with GABAA Receptor Subunit Mutations
Authors: Macdonald Robert L. , Kang Jing-Qiong
Published: December 2008

Mutations in ligand-gated ion channel genes associated with idiopathic generalized epilepsies have been reported in excitatory acetylcholine receptor α4 and β2 subunit genes linked to autosomal dominant nocturnal frontal lobe epilepsy and in inhibitory GABAA receptor α1, β3, γ2, and δ subunit genes associated with childhood absence epilepsy, juvenile myoclonic epilepsy, pure febrile seizures, generalized epilepsy with febrile seizures plus, and generalized epilepsy with tonic–clonic seizures. Recent studies suggest that these mutations alter receptor function or biogenesis, including impaired receptor subunit messenger RNA stability, receptor sub-unit protein folding and stability, receptor assembly, and receptor trafficking.
Making Generalizations about Seizure Propagation
Authors: Merlin Lisa R.
Published: December 2008

The Source of Afterdischarge Activity in Neocortical Tonic–Clonic Epilepsy. Trevelyan AJ, Baldeweg T, van Drongelen W, Yuste R, Whittington M. J Neurosci 2007;27(49):13513–13519. Tonic–clonic seizures represent a common pattern of epileptic discharges, yet the relationship between the various phases of the seizure remains obscure. Here we contrast propagation of the ictal wavefront with the propagation of individual discharges in the clonic phase of the event. In an in vitro model of tonic–clonic epilepsy, the after discharges (clonic phase) propagate with relative uniform speed and are independent of the speed of the ictal wavefront (tonic phase). For slowly propagating ictal wave fronts, the source of the afterdischarges, relative to a given recording electrode, switched as the wavefront passed by, indicating that afterdischarges are seeded from wavefront itself. In tissue that has experienced repeated ictal events, the wavefront generalizes rapidly, and the afterdischarges in this case show a different “flip-flop” pattern, with frequent switches in their direction of propagation. This same flip-flop pattern is also seen in subdural EEG recordings in patients suffering intractable focal seizures caused by cortical dysplasias. Thus, in both slowly and rapidly generalizing ictal events, there is not a single source of afterdischarge activity: rather, the source is continuously changing. Our data suggest a complex view of seizures in which the ictal event and its constituent discharges originate from distinct locations.
Novel Therapeutic Strategies for Epilepsy—Releasing the Gene Genie
Authors: Sills Graeme J.
Published: December 2008

Neuropeptide Y Gene Therapy Decreases Chronic Spontaneous Seizures in a Rat Model of Temporal Lobe Epilepsy. Noe F, Pool AH, Nissinen J, Gobbi M, Bland R, Rizzi M, Balducci C, Ferraguti F, Sperk G, During MJ, Pitkanen A, Vezzani A. Brain 2008;131(Pt 6):1506–1515. Temporal lobe epilepsy remains amongst the most common and drug refractory of neurological disorders. Gene therapy may provide a realistic therapeutic approach alternative to surgery for intractable focal epilepsies. To test this hypothesis, we applied here a gene therapy approach, using a recombinant adeno-associated viral (rAAV) vector expressing the human neuropeptide Y (NPY) gene, to a progressive and spontaneous seizure model of temporal lobe epilepsy induced by electrical stimulation of the temporal pole of the hippocampus, which replicates many features of the human condition. rAAV-NPY or a control vector lacking the expression cassette (rAAV-Empty) was delivered into the epileptic rat hippocampi at an early progressive stage of the disease. Chronic epileptic rats were video-EEG monitored to establish pre-injection baseline recordings of spontaneous seizures and the effect of rAAV-NPY versus rAAV-Empty vector injection. Both non-injected stimulated controls and rAAV-empty injected rats showed a similar progressive increase of spontaneous seizure frequency consistent with epileptogenesis. The delivery of rAAV-NPY in epileptic rat brain leads to a remarkable decrease in the progression of seizures as compared to both control groups and this effect was correlated with the NPY over-expression in the hippocampus. Moreover, spontaneous seizure frequency was significantly reduced in 40% of treated animals as compared to their pre-injection baseline. Our data show that this gene therapy strategy decreases spontaneous seizures and suppresses their progression in chronic epileptic rats, thus representing a promising new therapeutic strategy.
To Depolarize or Hyperpolarize? at the Axon Initial Segment, EGABA Sets the Stage
Authors: Stafstrom Carl E.
Published: December 2008

GABAergic Depolarization of the Axon Initial Segment in Cortical Principal Neurons Is Caused by the Na-K-2Cl Cotransporter NKCC1. Khirug S, Yamada J, Afzalov R, Voipio J, Khiroug L, Kaila K. J Neurosci. 2008;28(18):4635–4639. GABAergic terminals of axo-axonic cells (AACs) are exclusively located on the axon initial segment (AIS) of cortical principal neurons, and they are generally thought to exert a powerful inhibitory action. However, recent work (Szabadics et al., 2006) indicates that this input from AACs can be depolarizing and even excitatory. Here, we used local photolysis of caged GABA to measure reversal potentials ( EGABA) of GABAA receptor-mediated currents and to estimate the local chloride concentration in the AIS compared with other cellular compartments in dentate granule cells and neocortical pyramidal neurons. We found a robust axo-somato-dendritic –gradient in which the EGABA values from the AIS to the soma and dendrites become progressively more negative. Data from NKCC1-/- and bumetanide-exposed neurons indicated that the depolarizing EGABA at the AIS is set by chloride uptake mediated by the Na–K–2Cl cotransporter NKCC1. Our findings demonstrate that spatially distinct interneuronal inputs can induce postsynaptic voltage responses with different amplitudes and polarities as governed by the subcellular distributions of plasmalemmal chloride transporters.
Production Assistance for Cellular Therapies (PACT): four‐year experience from the United States National Heart, Lung, and Blood Institute (NHLBI) contract research program in cell and tissue therapies
Authors: Reed William , Noga Stephen J. , Gee Adrian P. , Rooney Cliona M. , Wagner John E. , McCullough Jeffrey , McKenna David H. , Whiteside Theresa L. , Donnenberg Albert D. , Baker Acacia K. , Lindblad Robert W. , Wagner Elizabeth L. , Mondoro Traci Heath
Published: December 2008

BACKGROUND: In 2002, the US National Heart, Lung, and Blood Institute (NHLBI) conducted a workshop to determine needs of the cell therapy community. A consensus emerged that improved access to cGMP facilities, regulatory assistance, and training would foster the advancement of cellular therapy.

STUDY DESIGN AND METHODS: A 2003 NHLBI request for proposals resulted in four contracts being awarded to three cell‐manufacturing facilities (Baylor College of Medicine, University of Minnesota, and University of Pittsburgh) and one administrative center (The EMMES Corporation). As a result, Production Assistance for Cellular Therapies (PACT) was formed.

RESULTS: As of October 1, 2008, PACT has received 65 preliminary applications of which 45 have been approved for product manufacture. A variety of cell therapies are represented including T‐regulatory cells, natural killer cells, adipose‐derived stem cells, cardiac progenitor cells for cardiac disease, hematopoietic progenitor cells (HPCs) for central nervous system applications, cytotoxic T lymphocytes, and dendritic cells. A total of 169 products have been administered under 12 applications and 2 reagents were manufactured and delivered. Fourteen peer‐reviewed publications and 15 abstracts have resulted from the PACT project to date. A cell therapy textbook is nearly complete. PACT technical projects have addressed assay development, rapid endotoxin testing, shipping of cell products, and CD34+ HPC isolation from low‐volume marrow. Educational Web seminars and onsite training through workshops have been conducted.

CONCLUSIONS: PACT is an active and successful cell therapy manufacturing resource in the United States, addressing research and training while forging relationships among academia, industry, and participating institutions.
The JAL antigen (RH48) is the result of a change in RHCE that encodes Arg114Trp
Authors: Westhoff Connie M. , Vege Sunitha , Wylie Dwane , Nickle Pam , Lomas‐Francis Christine , Hue‐Roye Kim , Reid Marion E.
Published: December 2008

BACKGROUND: The JAL antigen (Rh48) was discovered more than 30 years ago when it caused hemolytic disease of the fetus and newborn in an African American family. A decade later it was found to cause hemolytic disease of the fetus and newborn in a Caucasian family. The presence of the same low‐prevalence antigen in two different ethnic groups is rare, but additional JAL+ in both groups was subsequently identified. This study was undertaken to investigate the RH gene(s) responsible for expression of JAL and to determine the structural relationship between JAL and other Rh antigens.

STUDY DESIGN AND METHODS: Samples from 17 JAL+ people were included: 2 Caucasian, 6 African American, 7 African Brazilian, 1 Caribbean, and 1 Puerto Rican. RHCE and RHD were investigated at the genomic level, and Rh cDNAs were cloned and sequenced for some samples.

RESULTS: Caucasian JAL+ probands had RHCE*Ce, while JAL+ probands with African ancestry had RHCE*ce, but all had a nucleotide 340C>T change in Exon 3 of RHCE predicted to encode Arg114Trp. The JAL‐encoding RHCE*ce also had 733C>G (Leu245Val) and was linked to conventional RHD or to RHD*DAU0.

CONCLUSIONS: JAL+ results from a nucleotide 340C>T (Arg114Trp) on either a Ce or ce background. Homology modeling of the JAL+ RhCE protein suggests that the Arg→Trp change eliminates a critical loop‐stabilizing H‐bond between the side chain of Arg114 and the e‐specific amino acid Ala226. Additionally, accommodation of the bulky tryptophan would disrupt the conformation of the extracellular loops containing C/c‐ and e‐specific amino acids, providing a structural hypothesis for the simultaneous altered expression of C/c, e, and V/VS antigens.
Use of Fuzzy Evidential Reasoning in Maritime Security Assessment
Authors: Yang Z. L. , Wang J. , Bonsall S. , Fang Q. G.
Published: December 2008

Over the last few years, there has been a growing international recognition that the security performance of the maritime industry needs to be reviewed on an urgent basis. A large number of optional maritime security control measures have been proposed through various regulations and publications in the post‐9/11 era. There is a strong need for a sound and generic methodology, which is capable of taking into account multiple selection criteria such as the cost effectiveness of the measures based on reasonable security assessment. The use of traditional risk assessment and decision‐making approaches to deal with potential terrorism threats in a maritime security area reveals two major challenges. They are lack of capability of analyzing security in situations of high‐level uncertainty and lack of capability of processing diverse data in a utility form suitable as input to a risk inference mechanism. To deal with such difficulties, this article proposes a subjective security‐based assessment and management framework using fuzzy evidential reasoning (ER) approaches. Consequently, the framework can be used to assemble and process subjective risk assessment information on different aspects of a maritime transport system from multiple experts in a systematic way. Outputs of this model can also provide decisionmakers with a transparent tool to evaluate maritime security policy options for a specific scenario in a cost‐effective manner.
Risk Assessment for Hospital‐Acquired Diseases: A Risk‐Theory Approach
Authors: Emily Mathieu , Casez Pierre , François Olivier
Published: December 2008

We introduce a new approach to hospital‐acquired disease risk assessment from public health databases. In a spirit similar to actuarial risk theory, we define an adjustment coefficient that can quantify the risk associated with a hospital department, allowing comparisons of similar departments. The adjustment coefficient characterizes the tail of the distribution of the total patient length of stay in a department before the first disease event occurs. We show that this coefficient is the solution of a Lundberg‐like equation, and we provide a nonparametric estimation procedure for this measure, based on a Cramér‐Lundberg approximation for the tail of the distribution. Using simulations, we provide evidence of the robustness of the approximation to various individual risk models. In addition, we illustrate the relevance of this approach by evaluating the risk associated with a standard patient safety indicator in 20 hospitals of southeastern France.
Model‐Averaged Benchmark Concentration Estimates for Continuous Response Data Arising from Epidemiological Studies
Authors: Noble Robert B. , Bailer A. John , Park Robert
Published: December 2008

Worker populations often provide data on adverse responses associated with exposure to potential hazards. The relationship between hazard exposure levels and adverse response can be modeled and then inverted to estimate the exposure associated with some specified response level. One concern is that this endpoint may be sensitive to the concentration metric and other variables included in the model. Further, it may be that the models yielding different risk endpoints are all providing relatively similar fits. We focus on evaluating the impact of exposure on a continuous response by constructing a model‐averaged benchmark concentration from a weighted average of model‐specific benchmark concentrations. A method for combining the estimates based on different models is applied to lung function in a cohort of miners exposed to coal dust. In this analysis, we see that a small number of the thousands of models considered survive a filtering criterion for use in averaging. Even after filtering, the models considered yield benchmark concentrations that differ by a factor of 2 to 9 depending on the concentration metric and covariates. The model‐average BMC captures this uncertainty, and provides a useful strategy for addressing model uncertainty.
The Effects of Rate‐Adaptive Atrial Pacing Versus Ventricular Backup Pacing on Exercise Capacity in Patients with Left Ventricular Dysfunction
Authors: PASSMAN ROD , BANTHIA SMRITI , GALVEZ DINITA , SHELDON TODD , KADISH ALAN
Published: December 2008

Background: Atrial rate‐adaptive pacing may improve cardiopulmonary reserve in patients with left ventricular dysfunction.

Methods: A randomized, blinded, single‐crossover design enrolled dual‐chamber implantable defibrillator recipients without pacing indications and an ejection fraction ≤40% to undergo cardiopulmonary exercise treadmill stress testing in both atrial rate‐adaptive pacing (AAIR) and ventricular demand pacing (VVI) pacing modes. The primary endpoint was change in peak oxygen consumption (VO2). Secondary endpoints were changes in anaerobic threshold, perceived exertion, exercise duration, and peak blood pressure.

Results: Ten patients, nine males, eight with New York Heart Association class I, mean ejection fraction 24 ± 7%, were analyzed. Baseline VO2 was 3.6 ± 0.5 mL/kg/min. Heart rate at peak exercise was significantly higher during AAIR versus VVI pacing (142 ± 18 vs 130 ± 23 bpm; P = 0.05). However, there was no difference in peak VO2 (AAIR 23.7 ± 6.1 vs VVI 23.8 ± 6.3 mL/kg/min; P = 0.8), anaerobic threshold (AAIR 1.3 ± 0.3 vs VVI 1.2 ± 0.2 L/min; P = 0.11), rate of perceived exertion (AAIR 7.3 ± 1.5 vs VVI 7.8 ± 1.2; P = 0.46), exercise duration (AAIR 15 minutes, 46 seconds ± 2 minutes, 54 seconds vs VVI 16 minutes, 3 seconds ± 2 minutes, 48 seconds; P = 0.38), or peak systolic blood pressure (AAIR 155 ± 22 vs VVI 153 ± 21; P = 0.61) between the two pacing modes.

Conclusion: In this study, AAIR pacing did not improve peak VO2, anaerobic threshold, rate of perceived exertion, or exercise duration compared to VVI backup pacing in patients with left ventricular dysfunction and no pacing indications.
Atrial Fibrillation Therapy in Patients with a CRT Defibrillator with Wireless Telemetry
Authors: CROSSLEY GEORGE H. , AONUMA KAZUTAKA , HAFFAJEE CHARLES , SHODA MORIO , MEIJER ALBERT , BAUER ALEXANDER , BORIANI GIUSEPPE , SVENDSEN JESPER , THOMAS SHELLEY , WIGGENHORN CHRISTOPHER , UNTERBERG‐BUCHWALD CHRISTINA ,   for the Concerto‐AT Study Investigators
Published: December 2008

Background: Atrial fibrillation (AF) is a major cause of morbidity and mortality, especially in patients with congestive heart failure.

Objectives: The purposes of this international, prospective multicenter study were to evaluate the efficacy of atrial shock therapy in patients with a cardiac resynchronization therapy defibrillator (CRT‐D) and to evaluate the safety of the new CRT‐D. The effectiveness of a new wireless telemetry system was also evaluated.

Methods: A total of 282 patients, without permanent AF, who had indications for a CRT‐D were included. Atrial shock therapy was tested on both spontaneous and induced AF episodes. The effectiveness of the Medtronic wireless telemetry system (Conexus; Medtronic Inc., Minneapolis, MN, USA) was also tested. Secondary endpoints included the heart failure Clinical Composite Response, system performance evaluation, and adverse event summary.

Results: Atrial shock therapy was successful in 168 of 171 episodes (98.2%). Of these, 138 episodes were induced and 33 were spontaneous. Successful cardioversion occurred in 137 of the 138 induced‐AF episodes (86.1% with 12 joule (J), 13.1% with 24 J, and 0.7% with 35 J). During the first 3 months of implant, there were 43 system‐related complications in 37 subjects out of 278 subjects. There were 1,999 Conexus telemetry uses recorded during this study. This includes 282 uses during the implant procedure. There were no cases of complete loss of telemetry or any adverse events reported using this system.

Conclusion: We achieved an atrial shock efficacy of 98.2% in patients who met standard CRT‐D indications. The wireless telemetry performed well with no reported unanticipated adverse device effects.
The Effect of Dofetilide on Ventricular Defibrillation Thresholds
Authors: SIMON RON D. B. , STURDIVANT J. LACY , LEMAN ROBERT B. , WHARTON J. MARCUS , GOLD MICHAEL R.
Published: December 2008

Introduction: High defibrillation threshold (DFT) with an inadequate defibrillation safety margin remains an infrequent but troubling problem associated with defibrillator implantation. Dofetilide is a selective class III antiarrhythmic drug that reduces DFTs in a canine model. We hypothesized that dofetilide would reduce DFTs in humans, obviating the need for complex lead systems.

Methods and Results: Sixteen consecutive patients with DFTs ≥20 J delivered energy at implant‐received dofetilide therapy and underwent follow‐up DFT testing acutely following drug loading and/or chronically (128 ± 94 days). Amiodarone was discontinued in four patients at implantation. With dofetilide, DFTs decreased from 28 ± 4 J to 19 ± 7 J (P < 0.0001), resulting in a safety margin of 15 ± 8 J for the implanted devices. Five patients subsequently had spontaneous arrhythmias terminated successfully with shocks.

Conclusion: Dofetilide reduces DFTs sufficiently to prevent the need for more complex lead systems. This strategy should be considered when an inadequate defibrillation safety margin is present.
Spinal Cord Stimulation and 30‐Minute Heart Rate Variability in Refractory Angina Patients
Authors: ANSELMINO MATTEO , RAVERA LAURA , DE LUCA ANNA , CAPRIOLO MICHELE , BORDESE ROBERTO , TREVI GIAN P. , GRIMALDI ROBERTO
Published: December 2008

Background: Spinal cord stimulation (SCS) has proven antianginal and antiischemic effects in severe coronary artery disease patients, minimizing frequency, intensity, and duration of pain. The mechanism explaining these effects has been detected in a sympathicolytic effect of the SCS. We monitored 30‐minute‐long recordings of the heart rate variability (HRV) and its spectral power parameters to evaluate the influence of SCS on the sympathetic/parasympathetic balance.

Methods and Results: Eight patients underwent HRV recordings in controlled environmental conditions. The patients were seated in a relaxed position and isolated from external contacts. During three consecutive 30‐minute periods, the SCS was programmed, in a randomized fashion, to stimulate at a level generating paresthesias (ON), at a subliminal level (SUB, amplitude 80% of ON), or switched off (OFF). The low‐frequency/high‐frequency ratio during stimulation (ON) was significantly lower compared to that found while the SCS was turned OFF (0.54, 0.35–1.04 vs 1.21, 0.80–2.48; P = 0.036). The stimulation resulted in a median 52% (33–65%) reduction of the sympathetic activity compared to basal (ON vs OFF, P = 0.049).

Conclusion: No difference emerged instead comparing OFF versus SUB (P = 0.575). The stimulation effect was not influenced by the randomized sequence. Thirty‐minute SCS significantly influenced the sympathetic/parasympathetic balance reducing sympathetic modulation.
Vagal Enhancement as Evidence of Residual Ischemia After Inferior Myocardial Infarction
Authors: KAWASAKI TATSUYA , AKAKABE YOSHIKI , YAMANO MICHIYO , MIKI SHIGEYUKI , KAMITANI TADAAKI , KURIBAYASHI TOSHIRO , MATSUBARA HIROAKI , SUGIHARA HIROKI
Published: December 2008

Background: Acute inferior myocardial infarction (MI) often induces transient sinus bradycardia through vagal enhancement, known as Bezold‐Jarisch reflex, which is explained by preferential distribution of vagal nerve in the inferior wall. We examined vagal activity in relation to the occurrence of residual ischemia in patients with old inferior MI and assessed its diagnostic usefulness.

Methods: Exercise myocardial scintigraphy was performed in 15 patients with old inferior MI, 19 angina pectoris (AP) patients with inferior ischemia but no MI, and 32 control subjects who had no evidence of cardiac disease. We analyzed the connection of residual ischemia in old MI with ST‐segment response to exercise and with vagal activity as determined by coefficient of component variance of high frequency (CCVHF).

Results: Exercise‐induced percentage change in CCVHF was higher in patients with old MI and residual ischemia (18.8 ± 13.5%) and AP (5.5 ± 9.7%) than old MI but no residual ischemia (–24.1 ± 4.9%) or control (–22.8 ± 4.5%, P = 0.006). Percentage change in CCVHF > –5% had a good diagnostic value for the detection of residual ischemia in patients with old inferior MI with sensitivity of 83%, specificity of 89%, accuracy of 87%, and positive likelihood ratio of 7.50, which was higher than that of ST‐segment depression (67%, 50%, 56%, and 1.33).

Conclusions: Vagal enhancement was associated with residual ischemia in old inferior MI as well as inferior AP. Measurement of CCVHF is useful in improving the diagnostic reliability of exercise electrocardiography in patients with old inferior MI.
Diagnosis of Paroxysmal Atrial Fibrillation in Patients with Implanted Pacemakers: Relationship to Symptoms and Other Variables
Authors: QUIRINO GIANLUCA , GIAMMARIA MASSIMO , CORBUCCI GIORGIO , PISTELLI PAOLO , TURRI ELENA , MAZZA ANTONIO , PERUCCA ANTONELLO , CHECCHINATO CATIA , DALMASSO MAURIZIO , BAROLD S. SERGE
Published: December 2008

Background: Atrial fibrillation (AF) is not always accompanied by clear‐cut symptoms and symptoms suggestive of AF may not correspond to a genuine AF episode. The study prospectively evaluated the burden of asymptomatic AF episodes in pacemaker patients (for sick sinus syndrome) with a history of documented paroxysmal AF.

Methods: Consecutive patients were enrolled and implanted with dual‐chamber pacemakers equipped with diagnostic features for AF monitoring. Each patient was instructed about typical AF symptoms and was asked to keep a detailed log of symptoms. Stored pacemaker data were analyzed using only AF episodes >30 s.

Results: The mean follow‐up was 16 ± 6 months and 102 patients were enrolled (73 ± 7 years, 59 M). Thirteen patients (13%) dropped out with the development of permanent AF and their data were discarded. Twenty‐three patients (26%) without device‐stored AF episodes all reported at least one annotated AF episode. There were 1,245 device‐stored AF episodes in 66 (74%) out of 89 patients. Patients reported 1,141 episodes of AF‐related symptoms. Only 240 (21%) corresponded to a genuine device‐stored AF event. The sensitivity and positive predictive value of symptoms to detect AF were respectively 19% and 21%. Episode duration, rate increase at the onset of the arrhythmia, heart disease, or antiarrhythmic drug therapy showed no statistically significant differences comparing symptomatic and asymptomatic episodes.

Conclusions: Many pacemaker patients with paroxysmal AF can develop AF‐like symptoms in the absence of device‐stored AF. AF‐related symptoms have low sensitivity and low positive predictive value in patients with permanent pacemakers.
Systematic Comparisons of Electrocardiographic Morphology Increase the Precision of QT Interval Measurement
Authors: HNATKOVA KATERINA , SMETANA PETER , TOMAN ONDREJ , BAUER AXEL , SCHMIDT GEORG , MALIK MAREK
Published: December 2008

Decreased intrasubject variability of QTc values is needed to increase the power and reduce the size of the so‐called thorough QT studies. One source of QTc variability is the lack of systematic measurements when electrocardiograms (ECG) with closely matching morphologies are not measured in an exactly corresponding way. The inaccuracy can be eliminated by postprocessing of QT measurements by ECG pattern matching. This study tested the effects of pattern matching in ECG measurements in two populations of healthy subjects (n = 48 + 56) and in a population of patients with advanced Parkinson's disease (n = 130) in whom both day‐time and night‐time data were available. Intrasubject QTc variability was measured by intrasubject standard deviations (SD) of QTc values obtained with manual measurements before and after pattern‐matching measurement alignments. In each subject, QT values (n = 230–320) in one drug‐free long‐term ECG recording were evaluated. The pattern‐matching adjustment of the QT measurement decreased the intrasubject QTc variability from 5.2 ± 1.0 to 4.5 ± 1.0 ms (P < 10−14) from 6.4 ± 1.7 to 5.5 ± 1.6 ms (P < 10−10) from 5.6 ± 1.5 to 4.6 ± 1.4 ms (P < 10−34) and from 6.1 ± 1.9 to 5.0 ± 1.7 ms (P < 10−33), in the two populations of healthy subjects and in the day‐time and night‐time recordings of Parkinson's disease patients, respectively. Hence, morphological pattern adjustment of QT interval measurements improves the quality of the QT data with substantial practical implications. Reductions in intrasubject QTc variability were reproducibly found in different populations and thus the technology might be recommended for every thorough QT/QTc study. Noticeable reductions of necessary study size are likely achievable in this way.
Treatment of Inappropriate Sinus Tachycardia with Ivabradine in a Patient with Postural Orthostatic Tachycardia Syndrome and a Dual Chamber Pacemaker
Authors: KHAN SITARA , HAMID SHOAIB , RINALDI CHRISTOPHER
Published: December 2008

We present the case of a 44‐year‐old woman with postural orthostatic tachycardia syndrome (POTS) and a dual chamber pacemaker. The patient suffered from inappropriate sinus tachycardia that had been resistant to treatment with traditional rate‐slowing medications. Ivabradine—the specific sinus node If current inhibitor—was used to successfully lower the heart rate. The patient had no evidence of POTS on repeat autonomic function testing, and there was a corresponding symptomatic benefit. We propose that this class of drugs, the use of which is established as antianginals, should be considered in patients with resistant inappropriate sinus tachycardia.
Isoelectric PVCs Diagnosed with a Monitor with Simultaneous ECG, and ICD Intracardiac Electrogram and Marker Channels
Authors: SCHER DAVID L. , MAN DAVID C. , EDERY THOMAS , LU STEVEN
Published: December 2008

A 78‐year‐old woman with a remote history of chronic atrial fibrillation and catheter ablation of the atrioventricular node with a permanent ventricular pacemaker sustained a syncopal episode. Interrogation of her pacemaker revealed electrograms of ventricular fibrillation with a duration of 26 seconds. The patient underwent upgrade to an implantable cardioverter defibrillator (ICD). Postimplant, on telemetry, pauses were seen without pacing artifact, suspicious for oversensing of something by the ICD. Interrogation and threshold testing of the ICD established that both sensing (of her junctional escape rhythm) and pacing thresholds were excellent. A Holter monitor was utilized to evaluate the patient's rhythm and device function. It incorporated simultaneous tracings from multiple surface electrocardiogram leads and both intracardiac electrograms and marker channel recordings from the ICD. The causes for the pauses were found to be isoelectric premature ventricular complexes not seen on the telemetry tracings.
Lead‐Induced Tricuspid Stenosis—Successful Management by Balloon Angioplasty
Authors: HUSSAIN TARIQUE , KNIGHT WILLIAM BRODIE , McLEOD KAREN A.
Published: December 2008

We describe a case of tricuspid stenosis in a young woman 11 years after endocardial ventricular lead implantation. The cause of the stenosis appears to have been perforation of the septal leaflet by the lead at the time of insertion. We further describe successful management with percutaneous balloon valvuloplasty without the need for lead removal.
Reverse Twiddler's Syndrome
Authors: VLAY STEPHEN C.
Published: December 2008

Twiddler's syndrome is classically described as withdrawal of pacing or defibrillator leads from their position in the heart as a result of arm motion or manipulation of the pulse generator site. Reverse Twiddler's syndrome is now reported as advancement of the leads into the heart by a similar repetitive motion but opposite in direction.
Detection Methods for Irradiated Foods
Authors: Chauhan Sulaxana Kumari , Kumar R. , Nadanasabapathy S. , Bawa A.S.
Published: December 2008

ABSTRACT:  Proper control of irradiation processing of food is very critical to facilitate international trade of irradiated foods and to enhance consumer confidence, consumer choice, and safety. Analytical detection of radiation‐processing of food is very important to implement quality control at all levels. An ideal detection method should measure a specific radiation effect, which is proportional to the dose and should not be affected by processing parameters and storage conditions or the length of time between irradiation processing and analysis. The detection of irradiated foods is mainly based on radiolysis of lipids, modification of amino acids, modification of DNA, modification of carbohydrates, formation of free radicals, release of hydrogen gas, alterations in microbial load, measurement of biological difference, and other physical methods.
Processing Techniques to Reduce Toxicity and Antinutrients of Cassava for Use as a Staple Food
Authors: Montagnac Julie A. , Davis Christopher R. , Tanumihardjo Sherry A.
Published: December 2008

ABSTRACT:  Cassava is a valuable source of food for developing countries, but it contains highly toxic cyanogen compounds and antinutrients. Cyanogens are found in 3 forms in cassava: cyanogenic glucoside (95% linamarin and 5% lotaustratin), cyanohydrins, and free cyanide. Different processing techniques exist to remove cyanogens and their effectiveness depends on the processing steps and the sequence utilized, and it often is time‐dependent. Pounding or crushing is the most effective for cyanogenic glucoside removal because it ruptures cell compartments, thus allowing direct contact between linamarin and the enzyme linamarase that catalyzes the hydrolytic breakdown. Crushing and sun‐drying cassava roots made into flour removes 96% to 99% of total cyanogens, whereas soaking and sun‐drying into lafun or fufu, or soaking and fermenting and roasting into gari or farina, removes about 98% of cyanogens. For cassava leaves, which have 10 times more cyanogens than roots, pounding and boiling in water is an efficient process to remove about 99% of cyanogens. Other strategies to reduce toxicity include development of low‐cyanogen cassava varieties and cassava transgenic lines with accelerated cyanogenesis during processing. Although phytate and polyphenols have antioxidant properties, they interfere with digestion and uptake of nutrients. Fermentation and oven‐drying are efficient processing methods to remove phytate (85.6%) and polyphenols (52%), respectively, from cassava roots. Sun‐drying the leaves, with or without prior steaming or shredding, removes about 60% phytate. Cassava is a nutritionally strategic famine crop for developing countries and, therefore, reducing its toxicity and improving its nutritional value is crucial.
Spatially contingent interactions between an exotic and native plant mediated through flower visitors
Authors: Cariveau Daniel P. , Norton Andrew P.
Published: December 2008

Exotic plants can negatively impact the fitness of native plants by changing the behavior of flower visitors and thus affecting pollen transfer. The presence of an exotic plant may decrease the visitation rate to native plants and thus increase pollen limitation. Flower visitors may also switch between exotic and native plants and if pollen from an exotic plant is transferred to native plant stigmas this may impede siring by conspecific pollen. As flower visitors forage within a spatial context, the distribution of plants may affect the type and magnitude of pollinator‐mediated competition. In this study we examined two questions: 1) does the exotic plant, Carduus nutans (Asteraceae) interact with the native Monarda fistulosa (Lamiaceae) through flower visitors by changing visitation rate and/or through heterospecific pollen transfer, and does this affect seed set of the native plant? 2) Does spatial context affect how the native and exotic plants interact through flower visitors? We created plots containing potted M. fistulosa with and without the presence of potted C. nutans. In the presence of C. nutans, M. fistulosa stigmas had significantly fewer conspecific and more C. nutans pollen grains. Visitation rate and seed set tended to be lower in these invaded plots, however they were not significant. In a second experiment, we examined whether changes in visitation rate to M. fistulosa due to the presence of C. nutans was a function of M. fistulosa distance from C. nutans. We found that visitation rate did not decrease in the presence of C. nutans when M. fistulosa were adjacent to C. nutans or 15 meters from C. nutans. However, floral visitation rate to M. fistulosa decreased at 1 and 5 meters from C. nutans. Our results suggest interactions between plant species through flower visitors may depend on spatial scale.
Evaluating the relative importance of patch quality and connectivity in a damselfly metapopulation from a one‐season survey
Authors: Yamanaka Takehiko , Tanaka Koichi , Hamasaki Kenji , Nakatani Yukinobu , Iwasaki Nobusuke , Sprague David S. , Bjørnstad Ottar N.
Published: December 2008

The area‐and‐isolation paradigm, which has been the primary focus of metapopulation research, may not hold in some animal metapopulations if within‐patch preference is more important than patch area or connectivity. Recently, regression analyses have been used to evaluate the effect of patch connectivity and various patch qualities including area. However, their relative importance is not easy to determine, because patch qualities and connectivity are often spatially autocorrelated. In this paper, we try to evaluate the relative importance of within‐patch quality, patch connectivity and spatial autocorrelation using variation partitioning methods from community ecology. We constructed three regression models: within‐patch quality, PCNM (principal coordinates of neighbor matrices) and patch connectivity based on a one‐season survey of a damselfly Copera annulata metapopulation. The contribution of within‐patch quality was larger than that of connectivity. There was no prominent effect of patch area. We conclude that the area‐and‐isolation paradigm is not applicable to this C. annulata metapopulation. The spatial autocorrelation extracted by PCNM had the largest contribution; it contained almost all of the variation of connectivity and overlapped with variation explained by within‐patch quality. Connectivity corresponded most closely to medium‐scale spatial structure captured by PCNM (ca 640 m). The mean effective dispersal scale was estimated to be 53 m. Within‐patch quality, debris accumulation and vegetation cover in the pond corresponded with the medium and small (ca 201 m) spatial scales from PCNM, though we could not clearly explain the cause of this correspondence. We believe that our method will contribute to quick and effective evaluation of spatial and non‐spatial aspects of metapopulation.
Intraspecific niche flexibility facilitates species coexistence in a competitive community with a fluctuating environment
Authors: Yamauchi Atsushi , Miki Takeshi
Published: December 2008

We analyzed the role of niche usage flexibility (i.e. niche width) in promoting species coexistence in competitive communities in a one‐dimensional niche space. We included two types of stochasticity, namely, a random sampling effect of community founding and environmental fluctuation. Fluctuation was further divided into two categories: niche‐independent fluctuation (synchronized over the niche space) and niche‐dependent fluctuation (variable among individual niche positions). In the analysis, two types of genetic and inheritance systems of individual niche position were considered, i.e. sexual reproduction with multiple loci and asexual reproduction with phenotypic plasticity. We found that niche usage flexibility promoted species diversity only under restricted situations when the environment was constant, but it generally promoted diversity when the environment fluctuated. In particular, under niche‐independent fluctuation, niche usage flexibility significantly enhanced species diversity. In contrast, the analysis also predicted that when niche flexibility was constant, species diversity decreased with increasing environmental correlation between neighboring niches.
Sampling designs of insect time series data: are they all irregularly spaced?
Authors: Beresford D. V. , Sutcliffe J. F.
Published: December 2008

Time series data are commonly obtained by trapping over a standardized period of time, for example daily or weekly. In this paper we present evidence that such sampling designs are inherently irregularly spaced due to the varying developmental rates and population parameters caused by changing temperatures during a sampling season. We modeled an exponentially growing population based on stable fly population growth rates, and then compare different sampling regimes to determine which produces the best estimate of population growth rate. These results are then compared to field data based on weekly sampling at three dairy farms in Ontario over two summers. Transforming catch numbers (N) to ln(N)/(number of degree days within the sampling period) corrects for the irregular spaced sampling in these data. These results support the use of measuring population parameters such as population growth rates in terms of degree days.
Determinants of dietary specialization: a comparison of two sympatric species of sea snakes
Authors: Brischoux François , Bonnet Xavier , Shine Richard
Published: December 2008

Why do some predator species specialize on only a single type of prey whereas others take a broad range? One critical determinant may be the ontogenetic range of body sizes of the predator compared to that of its prey. If any single prey taxon spans only part of the range of prey sizes ingestible by the predator, then the predator will be more likely to take multiple prey taxa. We exploit a model system that provides a robust opportunity to test this hypothesis. We studied two sympatric species of predatory sea snakes, similar in size and general ecology that feed on anguilliform fishes from different habitats in the Great Lagoon of New Caledonia. Eel species from soft‐bottom habitats must construct their own burrows, and thus tend to be more slender‐bodied and less variable in body size than eel species that inhabit variable‐sized crevices among hard coral. As a result, a laticaudine sea snake species (Laticauda saintgironsi) that feeds on hard‐coral‐dwelling eels relies primarily on a single prey species: juveniles take young eels whereas adults consume adult eels of the same species. In contrast, a laticaudine species (L. laticaudata) that forages on soft‐bottom eels switches its prey ontogenetically: juveniles take small eel species whereas adults consume large eel species. Thus, habitat‐imposed constraints on the range of body sizes within each prey taxon generate a striking difference in the degree of dietary specialization of two closely related, sympatric predator species.
Consumer and resource diversity effects on marine macroalgal decomposition
Authors: Godbold Jasmin A. , Solan Martin , Killham Ken
Published: December 2008

Few manipulative experiments that explicitly test the relationship between biodiversity and ecosystem function have focussed on regenerative processes such as decomposition and nutrient cycling. Of the studies that have taken place, most have concentrated on the effects of leaf litter diversity rather than the effects of consumer diversity on decomposition. In the present study, we established an in‐situ mesocosm experiment on an intertidal mudflat in the Ythan Estuary, Scotland, to investigate the interactive effects of consumer diversity, resource diversity and microbial activity on algal consumption and decomposition. We assembled communities of three commonly occurring macrofaunal species (Hediste diversicolor,Hydrobia ulvaeandLittorina littorea) in monoculture and all possible combinations of two and three species mixtures and supplied them with single vs two‐species mixtures of the algaeFucus spiralisandUlva intestinalis. Further, we also investigated whether algal decomposition changes nutrient remineralisation within the sediment by determining the C:N ratio of the surficial sediment. Data were analysed using extended linear regression with generalized least squares estimation to characterise the variance structure. We found that consumer species diversity effects are best explained by compositional effects and that species richness per se may not be the single most important determinant of resource use and decomposition in this community. Algal identity and invertebrate identity effects underpin the observed response and reflect species‐specific traits associated with algal consumption and processing. The role of the microbial community is comparatively weak, but strongly linked to faunal activities and behaviour. The C:N ratio of the sediment increased with consumer species richness, indicating increased mineralisation in more diverse communities. Overall, our results suggest that although consumer species richness effects per se are weak, decomposition and subsequent incorporation of resources is nevertheless dependent on the composition of the decomposer community, which, in turn, has important implications for biogeochemical nutrient cycling in marine coastal habitats.