bluuebunny/crossref_metadata_2025_split huggingface dataset:
Markers of Myocardial Damage, Tissue Healing, and Inflammation After Radiofrequency Catheter Ablation of Atrial Tachyarrhythmias
Authors: BRUECKMANN MARTINA , WOLPERT CHRISTIAN , BERTSCH THOMAS , SUESELBECK TIM , LIEBETRAU CLAUDIA , KADEN JENS J. , HUHLE GUENTER , NEUMAIER MICHAEL , BORGGREFE MARTIN , HAASE KARL K. 
Published: May 2004

Introduction: Radiofrequency ablation produces a localized endomyocardial necrosis that may result in release of biochemical markers reflecting myocardial cell damage, inflammation, and tissue reparation. The aim of this study was to determine the extent of rise and time course of markers of inflammation and tissue reparation in patients undergoing radiofrequency catheter ablation. Methods and Results: Serial blood samples were taken from patients with AV nodal reentrant tachycardia (n = 5), Wolff‐Parkinson‐White syndrome (n = 3), and atrial flutter (n = 5) undergoing radiofrequency ablation. Blood was taken before ablation (day 0, baseline) and at day 1 and day 120 after ablation. The proinflammatory marker interleukin‐6 (IL‐6), troponin I (TNI), and myoglobin, as well as matrix metalloproteinase‐9 (MMP‐9), a marker for myocardial healing, were measured by enzyme‐linked immunosorbent assay. Levels of IL‐6, TNI, myoglobin, and MMP‐9 were significantly elevated on day 1 after ablation compared to baseline levels. Seven of the 13 patients had troponin levels greater than the threshold of significant myocardial damage (>0.1 ng/mL) on day 1. Plasma levels of MMP‐9 were still elevated on day 120 compared to values before ablation (P = 0.021). Conclusion: Markers of inflammation, wound healing, and myocardial damage are increased in patients who undergo radiofrequency ablation. Levels of MMP‐9, a marker for myocardial healing and repair, are still elevated 120 days after the procedure, suggesting that radiofrequency ablation induces tissue damage leading to a long‐term process of reparation. (J Cardiovasc Electrophysiol, Vol. 15, pp. 686‐691, June 2004)
On the Atrial Response to Focal Discharges in Man
Authors: RAMANNA HEMANTH , BAKKER JACQUES M.T. DE , ELVAN ARIF , RICHARD N.W. HAUER M.D.  
Published: May 2004

Introduction: Triggers and vulnerability are key factors for the occurrence of atrial fibrillation (AF). The aim of this study was to assess spatial dispersion of atrial refractoriness and vulnerability in response to both focal discharges as well as programmed electrical stimulation in patients undergoing ablation of atrial arrhythmogenic foci. Methods and Results: Twenty‐nine patients were studied, and 12 right atrial unipolar electrograms were recorded. Inducibility of AF was assessed by a pacing protocol that started with one extrastimulus, followed by more aggressive pacing until AF was obtained. Mean fibrillatory intervals were used to assess the local refractoriness of each recording site. Spatial dispersion of refractoriness was calculated as the coefficient of dispersion (CD value: standard deviation of the mean of all local mean fibrillatory intervals as a percentage of the overall mean fibrillatory interval). Based on our previous study, a CD value ≤ 3.0 was defined as normal, whereas a CD value >3.0 was considered enhanced spatial dispersion of refractoriness. Fifteen of 29 patients had normal dispersion of refractoriness (mean CD value 1.65 ± 0.43), and AF was inducible with burst pacing only. These patients had focal discharges causing rapid atrial tachycardia with a focal activation pattern. Activation mapping of focal activity was possible in 14 of 15 patients. Focal triggering of AF occurred in only 1 of 15 patients. Fourteen of 29 patients had enhanced dispersion (mean CD value 4.2 ± 0.72). AF was inducible with a single extrastimulus in 11 of 14 patients (P < 0.001). Focal triggering of AF occurred in all 14 patients. Conclusion: Spatial dispersion of atrial refractoriness determines whether focal atrial discharges trigger AF with disorganized activity or, alternatively, only rapid atrial tachycardia. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1‐8, June 2004)
Transmural Distribution of Connexins in Rodent Hearts
Authors: YAMADA KATHRYN A. , KANTER EVELYN M. , GREEN KAREN G. , SAFFITZ JEFFREY E. 
Published: May 2004

Introduction: Electrophysiologic heterogeneity across the ventricular wall is a result of differential transmural expression of various ion channel proteins that underlie the different action potential waveforms observed in epicardial, midmyocardial, and endocardial regions. Cardiac connexins mediate cell‐to‐cell communication, are critical for normal impulse propagation, and play a role in electrophysiologic remodeling in disease states. However, little is known about the transmural distribution of cardiac gap junction proteins. Methods and Results: Connexin expression in epicardium, midmyocardium, and endocardium was assessed immunohistochemically in mouse and rat hearts. The total connexin protein content within different ventricular regions was measured by immunoblotting. Connexin43 is twice as abundant in midmyocardium and endocardium compared with epicardium in the mouse but not in the rat. Connexin45 is expressed equally across the left ventricular wall. Conclusion: Epicardial myocytes express significantly less Cx43 and therefore may be less well coupled than midmyocardial and endocardial myocytes. A transmural gradient of connexin43 expression across the left ventricular free wall likely results in differences in the stoichiometry of connexins expressed in different regions of the heart. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1‐6, June 2004)
The Restitution Portrait:
Authors: KALB SOMA S. , DOBROVOLNY HANA M. , TOLKACHEVA ELENA G. , IDRISS SALIM F. , KRASSOWSKA WANDA , GAUTHIER DANIEL J. 
Published: May 2004

Introduction: Electrical restitution, relating action potential duration (APD) to diastolic interval (DI), was believed to determine the stability of heart rhythm. However, recent studies demonstrate that stability also depends on long‐term APD changes caused by memory. This study presents a new method for investigation of rate‐ and memory‐dependent aspects of restitution and for assessment of mapping models of APD. Methods and Results: Bullfrog ventricular myocardium was paced with a “perturbed downsweep protocol.” Starting from a basic cycle length (BCL) of 1,000 ms, the tissue was paced until steady state was achieved, followed by single beats of longer and shorter cycle lengths. BCL was decreased by 50 to 100 ms and the process repeated. All APDs were plotted as a function of the preceding DI, which allowed simultaneous observation of dynamic, S1‐S2, and two constant‐BCL restitution curves in a “restitution portrait.” Responses were classified as 1:1 (stimulus:response), transient 2:2, or persistent 2:2 (alternans) and were related to the slopes of the restitution curves. None of these slopes approached unity for the persistent 2:2 response, demonstrating that the traditional restitution condition does not predict alternans. The restitution portrait was used to evaluate three mapping models of APD. The models with no memory and with one‐beat memory did not produce restitution portraits similar to the experimental one. A model with two‐beat memory produced a qualitatively similar portrait. Conclusion: The restitution portrait allows a more comprehensive assessment of cardiac dynamics than methods used to date. Further study of models with memory may result in a clinical criterion for electrical instability. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1‐12, June 2004)
Detection of Inadvertent Catheter Movement into a Pulmonary Vein During Radiofrequency Catheter Ablation by Real‐Time Impedance Monitoring
Authors: CHEUNG PETER , HALL BURR , CHUGH AMAN , GOOD ERIC , LEMOLA KRISTINA , HAN JIHN , TAMIRISA KAMALA , PELOSI FRANK , MORADY FRED , ORAL HAKAN 
Published: May 2004

Introduction: During radiofrequency ablation to encircle or isolate the pulmonary veins (PVs), applications of radiofrequency energy within a PV may result in stenosis. The aim of this study was to determine whether monitoring of real‐time impedance facilitates detection of inadvertent catheter movement into a PV. Methods and Results: In 30 consecutive patients (mean age 53 ± 11 years) who underwent a left atrial ablation procedure, the three‐dimensional geometry of the left atrium, the PVs, and their ostia were reconstructed using an electroanatomic mapping system. The PV ostia were identified based on venography, changes in electrogram morphology, and manual and fluoroscopic feedback as the catheter was withdrawn from the PV into the left atrium. Real‐time impedance was measured at the ostium, inside the PV at approximately 1 and 3 cm from the ostium, in the left atrial appendage, and at the posterior left atrial wall. There was an impedance gradient from the distal PV (127 ± 30 Ω) to the proximal PV (108 ± 15 Ω) to the ostium (98 ± 11 Ω) in each PV (P < 0.01). There was no significant impedance difference between the ostial and left atrial sites. During applications of radiofrequency energy, movement of the ablation catheter into a PV was accurately detected in 80% of the cases (20) when there was an abrupt increase of ≥4 Ω in real‐time impedance. Conclusion: There is a significant impedance gradient from the distal PV to the left atrium. Continuous monitoring of the real‐time impedance facilitates detection of inadvertent catheter movement into a PV during applications of radiofrequency energy. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1‐5, June 2004)
Ablation of Superior Pulmonary Veins Compared to Ablation of All Four Pulmonary Veins:
Authors: KATRITSIS DEMOSTHENES G. , ELLENBOGEN KENNETH A. , PANAGIOTAKOS DEMOSTHENES B. , GIAZITZOGLOU ELEFTHERIOS , KARABINOS ILIAS , PAPADOPOULOS ANASTASIOS , ZAMBARTAS CONSTANTINOS , ANAGNOSTOPOULOS CONSTANTINE E. 
Published: May 2004

Introduction: Isolation of all pulmonary veins (PV) is advocated for treatment of paroxysmal atrial fibrillation (PAF). However, the superior PVs are responsible for most AF triggers, whereas the inferior PVs carry the higher risk for ablation‐induced ostial stenosis. The aim of this study was to compare a superior PV isolation approach with isolation of all PVs for treatment of PAF. Methods and Results: Fifty‐two patients with PAF were randomized to either left superior pulmonary vein (LSPV) isolation followed by additional isolation of the right superior pulmonary vein (RSPV) in case of AF recurrence (group A, n = 27) or isolation of all four PVs followed by a repeat procedure in case of recurrence (group B, n = 25). At 1‐year follow‐up, 11 patients (41%) in group A and 8 patients (32%) in group B had AF relapse (P = 0.55). No significant differences in AF relapse were detected between groups at 3 and 12 months (log rank = 0.36, P = 0.54) and by Cox proportional hazards model analysis (P = 0.62). Nonsignificant PV stenosis was detected in two patients from group B. Total radiofrequency energy delivery and fluoroscopy and procedure times were lower in group A: 8.9 ± 1.4 minutes vs 25.6 ± 3.7 minutes (P < 0.001), 22.2 ± 6.8 minutes vs 62 ± 10.3 minutes (P < 0.001), and 131.8 ± 26.5 minutes vs 222.2 ± 32.3 minutes (P < 0.001), respectively. Conclusion. A staged superior PVs isolation approach confers equal success rates but with reduced radiofrequency energy delivery and fluoroscopy and procedure times compared to isolation of all PVs at the initial ablation attempt. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1‐5, June 2004)
Non‐destructive sources of DNA used to genotype honey bee (Apis mellifera) queens
Authors: Gregory Pamela G. , Rinderer Thomas E. 
Published: May 2004

AbstractWe describe a method for genotyping honey bee queens Apis mellifera L. (Hymenoptera: Apidae), using biological materials that are normally cast off during development (larval and pupal exuviae), or can be removed without apparent damage to queen longevity or acceptability to workers (wing clippings). Highly polymorphic microsatellite loci were successfully amplified from DNA from all of these sources, although with differing degrees of success. DNA was extracted using a simple Chelex 100® boiling procedure. Four microsatellite primers were used to amplify the DNA, and the PCR products were visualized on an ALFexpress Automated Sequencer. Genotypes created from these sources were consistent with those originating from tarsal tissue. Successful retrieval and amplification of DNA from the exuviae from immature queens allows potential breeding individuals to be genotyped and selected before they become adults. This procedure may therefore have value as DNA marker‐assisted breeding programs are developed for honey bees.
Effect of Bt corn leaf suspension on food consumption by Chilo partellus and life history parameters of its parasitoid Cotesia flavipes under laboratory conditions
Authors: Prütz G. , Dettner K. 
Published: May 2004

AbstractLaboratory scale experiments were conducted in order to assess the potential effect of Bacillus thuringiensis‐corn leaf material on the parasitized herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and on its parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). Food consumption and relative consumption rate of parasitized hosts exposed to Bt‐corn leaf‐material were strongly reduced compared to the control. The number of hosts allowing parasitoid larvae to complete their development was also reduced in the Bt group. Moreover, the fresh weight of parasitoid pupae and the dry weight of parasitoid adults was lower than in the control. Only in the Bt group, were strong negative correlations found between food intake by the host, and the number of parasitoid cocoons. Strong positive correlations were also only found in the Bt group, between food intake and parasitoid development time. As effects of Bt on the oviposition behaviour of C. flavipes could be excluded, differences between the Bt group and the control could only be due to the effect of Bt toxin on the parasitoid larva developing inside the host. Whenever food consumption can be measured, the methods used in this study are proposed as a model for future risk assessments on different types of insect‐resistant transgenic plants, herbivores, parasitoids, and predators.
The effect of photoperiod on walking, feeding, and oviposition in the western flower thrips
Authors: Whittaker Mark S. , Kirk William D. J. 
Published: May 2004

AbstractThe western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major pest in glasshouses, where light and photoperiod are often manipulated to grow crops. The effect of five photoperiods (L0:D24, L6:D18, L12:D12, L18:D6, and L24:D0) on the behaviour of adult females was investigated in the laboratory at 25 °C. The amount of walking, pollen consumption, and oviposition all increased with increasing photophase. The three behaviours occurred at a low rate in continuous darkness, and are therefore not exclusively diurnal. Three out of 16 thrips (19%) showed weakly rhythmic walking activity in continuous darkness, with an average circadian period of 25.3 ± 1.5 h. It is proposed that the length of the photophase determines the amount of nutrient intake, which in turn determines oviposition rate and thus affects population increase.
Oviposition preference of Anthocoris nemorum and A. nemoralis for apple and pear
Authors: Sigsgaard Lene 
Published: May 2004

Abstract Anthocoris nemorum L. and Anthocoris nemoralis Fabricius (Heteroptera: Anthocoridae) are important predators of insect pests in pome fruit. Females insert their eggs in leaf tissue. The females’ choice of oviposition site is important for the subsequent distribution of nymphs on host plants. Oviposition preference for apple and pear leaves was tested in the laboratory in four experiments (experiments 1–4). In three experiments it was tested whether simulated insect damage to leaves (experiments 5 and 6) or the presence of prey (experiment 7) influenced oviposition preference. The effect of the presence of prey was only tested for A. nemorum on apple leaves. There was a highly significant anthocorid species × plant interaction for the number of eggs laid on apple and pear leaves. Anthocoris nemorum laid more eggs on apple than on pear leaves, while A. nemoralis preferred pear. Anthocoris nemorum's preference for apple increased over the 6‐week period in which experiments 1–4 were performed, from 66% to 91% eggs laid on apple leaves. No change over time in preference was found for A. nemoralis. Across experiments 1–4, the majority of A. nemorum eggs were laid near leaf margins, whereas eggs of A. nemoralis were more commonly found in the leaf centre, 5 mm or more from the margin, with a highly significant leaf region × species interaction. There was no significant difference in preference for leaf side between A. nemorum and A. nemoralis, but there was a highly significant plant × leaf side × experiment interaction. Thus, more eggs were laid on the ventral than on the dorsal side of pear leaves in experiment 4, while significantly more eggs were laid on the dorsal side of apple leaves in experiments 3 and 4. Choice tests between damaged and healthy leaves showed that A. nemorum laid significantly more eggs on the damaged leaves, while A. nemoralis preferred healthy leaves. Anthocoris nemorum showed a near‐significant preference for ovipositing on leaves with eggs of Operophtera brumata (Lepidoptera: Geometridae). The oviposition preferences found correspond to the natural distribution of these predators in apple and pear orchards. The preference of A. nemorum for leaf margins, and of A. nemoralis for the leaf centre as an oviposition site, supports earlier observations. A preference for leaf side for oviposition site has not been reported earlier. Preference for damaged leaves could help A. nemorum to locate prey in a field situation.
Expression of the peroxidase gene promoter (Shpx6b) from Stylosanthes humilis in transgenic plants during insect attack
Authors: Perera Modika R. , Jones Michael G.K. 
Published: May 2004

AbstractInducible promoters are important in regulating the expression of resistance genes when plants are attacked by insects or pathogens. Evaluation of the Shpx6b peroxidase promoter from the tropical forage legume Stylosanthes humilis[Curtis MD, Rae AL, Rusu AG, Harrison SJ & Manners JM (1997) A peroxidase gene promoter induced by phytopathogens and methyl jasmonates in transgenic plants. Molecular Plant Microbial Interactions 10: 326–338] in transgenic tobacco plants Nicotiana tabacum L. (Solanaceae) demonstrated that this promoter could drive expression of both the β‐glucuronidase (GUS uidA gene of E. coli) and green fluorescent protein (GFP) reporter genes in leaf tissues during attack by chewing insects – larvae of potato tuber moth (PTM) Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae) and sucking insects – green peach aphids Myzus persicae Sulzer (Homoptera: Aphididae). Strong GUS expression was present in tissues next to cells damaged by PTM larvae 24 h after infestation. With aphid infestation, GUS expression was limited to sites of feeding, and was observed 48 h after infestation. The expression of GFP mirrored that of GUS expression for both treatments, but was normally detected 48 h after infestation. Similarly, the exogenous application of methyl jasmonate (MeJa) induced GUS uniformly across leaf tissue, and mechanical wounding activated GUS expression at wound sites, similar to PTM larvae. GFP expression was observed 48 h after treatment, and for mechanical wounding GFP was localised in a manner similar to PTM damage. For MeJa treatment, GFP expression was more pronounced in cells around the midrib, and it was not uniformly induced across the leaf tissue. GUS reporter gene levels were also assayed to quantify expression, and the results were consistent with the observed histological patterns of expression. The results presented here show that the Shpx6b promoter switches on the expression of linked genes after damage by insect herbivores, and could be useful in regulating the expression of heterologous genes for insect and/or pathogen resistance in transgenic plants.
The Ecological-Evolutionary Typology of Human Societies and the Evolution of Social Inequality
Authors: Nielsen FrançLois 
Published: May 2004

Gerhard Lenski's ecological-evolutionary typology of human societies, based on the level of technology of a society and the nature of its physical environment, is a powerful predictor of various dimensions of social inequality. Analysis of comparative data shows that while some dimensions of the stratification system (such as measures of social complexity) exhibit a monotonic trend of increasing inequality with level of technology from the hunting-and-gathering to the agrarian type, others (such as measures of freedom and sexual inequality among males) exhibit a pattern of “agrarian reversal” in which inequality increases from the hunting-and-gathering to the advanced horticultural type but then declines with the agrarian type. Theoretical and empirical implications of the agrarian reversal pattern for the study of social inequality are discussed. I am grateful to Bernice McNair Barnett and Gehard Lenski for comments and to Patrick Nolan for advice on coding societal type.
Learning from James: Lessons about Policy and Practice for Schools' Special Provision in the Area of Literacy Difficulties
Authors: Wearmouth Janice 
Published: May 2004

Janice Wearmouth is a senior lecturer in the Faculty of Education and Language Studies at the Open University in the UK. She has many years' experience of teaching and research in mainstream secondary schools and of developing and leading postgraduate development courses for teachers in the area of special and inclusive education. In this article, she argues that successive Governments in England, Wales and Northern Ireland have adopted policies in relation to special educational provision that are essentially technicist in character. These policies proceed from assumptions that are made about the clear and unproblematic nature of the issues and the responses that need to be made. In this model, difficulties in learning can be ‘fixed’ by selecting the most appropriate ‘tool’ in the most efficient and cost‐effective way. The current focus on competency‐based teacher education can be seen as a corollary of this approach.Drawing upon a personal account of the experience of having difficulties in literacy acquisition, this article presents a contrary view. Janice Wearmouth argues that the area of special educational needs in schools, including literacy difficulties, is fraught with uncertainty and conflicting viewpoints. Given this complex situation, the technicist responses of recent Governments in the UK seem inappropriate and inadequate, Janice Wearmouth suggests. She proposes that practice in relation to special educational needs in general, and literacy difficulties in particular, can be most effectively understood from the perspective of a reflective practitioner. Her article closes with a call for practitioner professional development to be reconceptualised in these terms.