bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unraveling thrombin's true microglia‐activating potential: markedly disparate profiles of pharmaceutical‐grade and commercial‐grade thrombin preparations
Authors: Weinstein Jonathan R. , Hong Soyon , Kulman John D. , Bishop Caroline , Kuniyoshi Jon , Andersen Henrik , Ransom Bruce R. , Hanisch Uwe‐Karsten , Möller Thomas 
Published: September 2005

AbstractMicroglia are the resident immune cells of the CNS. Brain injury triggers microglial activation, leading to proliferation, changes in antigenic profile, NO production and cytokine release. It is widely believed that serum factors inundating the injured tissue can prompt this activation, leading to long‐term phenotypic changes. We and others have recently reported that commercial‐grade preparations of thrombin, a serine protease known for its central function in blood coagulation, activate microglial cells. Recent findings, however, have called into question the involvement of thrombin itself in the induction of microglial cytokine release and led us to systematically re‐investigate the ability of the protease to induce a broad spectrum of microglial activation parameters. We used a pharmaceutical‐grade recombinant human thrombin (rh‐thr) and compared it with a commercial‐grade plasma‐derived bovine thrombin (pb‐thr) preparation that has been used extensively in the literature, including in our own earlier report. We investigated the effect of these two thrombin preparations on proliferation, NO production, interleukin‐6 and tumour necrosis factor‐α release, intracellular calcium signaling and cell surface expression of CD95 (Fas) and CD40. Pb‐thr induced robust responses in all variables tested. In contrast, rh‐thr triggered calcium signals and induced small but significant changes in the expression of cell surface antigens, but had no effect on proliferation, NO production or cytokine release. Control studies assured equivalent thrombin potencies and excluded both species‐specific effects and endotoxin (lipopolysaccharide) contamination as possible causes of the disparity. Our results indicate a substantially more restricted role for thrombin itself in microglial activation than previously appreciated, but point to several potentially important co‐stimulatory effects. In addition, these results suggest that previous studies examining thrombin's activation of microglia should be cautiously re‐interpreted.
Isolation, characterization and cross‐species amplification of microsatellite DNA loci in the tropical American yam Dioscorea trifida
Authors: HOCHU I. , SANTONI S. , BOUSALEM M. 
Published: September 2005

AbstractWe developed microsatellite markers in American yam (Dioscorea trifida). A microsatellite sequence‐enriched genomic library was screened, and after sequencing, primers were designed for 20 microsatellites. Among these, eight primer pairs yielded amplification products that were both interpretable and polymorphic in 24 yam cultivars. The number of alleles per locus ranged from two to 13 and the overall expected heterozygosity was around 0.5. Six of the eight Dioscorea trifida microsatellite loci gave amplification products in other Dioscorea species.
Isolation of polymorphic DNA microsatellites in the common sole Solea vulgaris
Authors: GAROIA FLAVIO , MARZOLA SILLA , GUARNIERO ILARIA , TRENTINI MASSIMO , TINTI FAUSTO 
Published: September 2005

AbstractA microsatellite‐enriched genomic library was obtained from the common sole, Solea vulgaris, and seven polymorphic dinucleotide markers were successfully optimized. These markers showed levels of expected heterozygosity ranging from 0.55 to 0.83 and allele number ranging from eight to 12. Three of these markers were also found to successfully amplify in the closely related Solea senegalensis and can be employed to define population genetic structure of the two Solea species and for inferring stock origins.
Late‐Life Anemia Is Associated with Increased Risk of Recurrent Falls
Authors: Penninx Brenda W. J. H. , Pluijm Saskia M. F. , Lips Paul , Woodman Richard , Miedema Kor , Guralnik Jack M. , Deeg Dorly J. H. 
Published: October 2005

Objectives: To examine whether anemia is associated with a higher incidence of recurrent falls.Design: Prospective cohort study.Setting: Community‐dwelling sample in the Netherlands.Participants: Three hundred ninety‐four participants aged 65 to 88 from the Longitudinal Aging Study Amsterdam.measurements: Anemia was defined according to World Health Organization criteria as a hemoglobin concentration less than 12 g/dL in women and less than 13 g/dL in men. Falls were prospectively determined using fall calendars that participants filled out weekly for 3 years. Recurrent fallers were identified as those who fell at least two times within 6 months during the 3‐year follow‐up.Results: Of the 394 persons, 11.9% (18 women and 29 men) had anemia. The incidence of recurrent falls was 38.3% of anemic persons versus 19.6% of nonanemic persons (P=.004). After adjustment for sex, age, body mass index, and diseases, anemia was significantly associated with a 1.91 times greater risk for recurrent falls (95% confidence interval=1.09–3.36). Poor physical function (indicated by muscle strength, physical performance, and limitations) partly mediated the association between anemia and incidence of recurrent falls.Conclusion: Late‐life anemia is common and associated with twice the risk of recurrent falls. Muscle weakness and poor physical performance appear to partly mediate this association.
Interatrial Electrical Connections: The Precise Location and Preferential Conduction
Authors: SAKAMOTO SHUN‐ICHIRO , NITTA TAKASHI , ISHII YOSUKE , MIYAGI YASUO , OHMORI HIROYA , SHIMIZU KAZUO 
Published: September 2005

Background: The atria are assumed to be connected electrically to each other at the level of the Bachmann's bundle, coronary sinus (CS) musculature, and interatrial septum, and these connections may have an important role in the interatrial conduction and perpetuation of various types of atrial tachyarrhythmias. However, the number, location, and preferential connections of the interatrial conduction related to the site of activation have not been examined yet. Methods: The endocardium of both atria and the CS were mapped during continuous pacing from the left superior and inferior pulmonary veins, right pulmonary veins, upper and lower right atrium, or right atrial septum at various paced cycle lengths in 14 canines. The electrograms were recorded by custom‐made form‐fitted electrodes mounted on a specially designed device that allowed the septal aspects of the electrode forms to be spatially fixed to each other accurately. Results: Four distinct interatrial electrical connections were identified at the Bachmann's bundle, CS, and antero‐superior and postero‐inferior septa. Decremental conduction was not seen in any of the connections. Bachmann's bundle was the most preferential connection during pacing from any epicardial site. The transseptal connections were evident only during pacing from the interatrial septum. The preference among the four connections was determined by the site of stimulation and the propagation of the activation related to the myocardial architecture. Conclusion: These unique preferential connections may play a significant role in the interatrial conduction and perpetuation of atrial tachyarrhythmias.
Validation of ECG Indices of Ventricular Repolarization Heterogeneity: A Computer Simulation Study
Authors: VAN HUYSDUYNEN BART HOOFT , SWENNE CEES A. , DRAISMA HARMEN H.M. , ANTONI M. LOUISA , VAN DE VOOREN HEDDE , VAN DER WALL ERNST E. , SCHALIJ MARTIN J. 
Published: September 2005

Introduction: Repolarization heterogeneity (RH) is functionally linked to dispersion in refractoriness and to arrhythmogenicity. In the current study, we validate several proposed electrocardiogram (ECG) indices for RH: T‐wave amplitude, ‐area, ‐complexity, and ‐symmetry ratio, QT dispersion, and the Tapex‐end interval (the latter being an index of transmural dispersion of the repolarization (TDR)). Methods and Results: We used ECGSIM, a mathematical simulation model of ECG genesis in a human thorax, and varied global RH by increasing the standard deviation (SD) of the repolarization instants from 20 (default) to 70 msec in steps of 10 msec. T‐wave amplitude, ‐area, ‐symmetry, and Tapex‐end depended linearly on SD. T‐wave amplitude increased from 275 ± 173 to 881 ± 456 μV, T‐wave area from 34 × 103± 21 × 103 to 141 × 103± 58 × 103μV msec, T‐wave symmetry decreased from 1.55 ± 0.11 to 1.06 ± 0.23, and Tapex‐end increased from 84 ± 17 to 171 ± 52 msec. T‐wave complexity increased initially but saturated at SD = 50 msec. QT dispersion increased modestly until SD = 40 msec and more rapidly for higher values of SD. TDR increased linearly with SD. Tapex‐end increased linearly with TDR, but overestimated it. Conclusion: T‐wave complexity did not discriminate between differences in larger RH values. QT dispersion had low sensitivity in the transitional zone between normal and abnormal RH. In conclusion, T‐wave amplitude, ‐area, ‐symmetry, and, with some limitations, Tapex‐end and T‐wave complexity reliably reflect changes in RH.
Chronic Hemodynamic Effects After Radiofrequency Catheter Ablation of Frequent Monomorphic Ventricular Premature Beats
Authors: SEKIGUCHI YUKIO , AONUMA KAZUTAKA , YAMAUCHI YASUTERU , OBAYASHI TOHRU , NIWA AKIHIRO , HACHIYA HITOSHI , TAKAHASHI ATSUSHI , NITTA JUNICHI , IESAKA YOSHITO , ISOBE MITSUAKI 
Published: September 2005

Introduction: Radiofrequency catheter ablation (RFCA) of severely symptomatic monomorphic ventricular premature beats (VPBs) is reported to be a safe and effective treatment option. However, the chronic hemodynamic effects of these VPBs have not been precisely evaluated. Methods and Results: We sought to investigate chronic effects after decreasing the number of VPBs by RFCA. A total of 47 patients who had no underlying heart disease and frequent monomorphic VPBs, consisting of more than 10,000 beats per day (24,194 ± 12,516 beats per day), were enrolled. Patients were treated with RFCA and followed up over 6 months as outpatients. Echocardiography and serum B‐type natriuretic peptide (BNP) level were repeatedly checked before and after RFCA. In 38 patients, whose VPBs were dramatically decreased to less than 1,000 beats per day by successful RFCA, left ventricular (LV) end‐diastolic dimension (LVEDd) and end‐systolic dimension (LVESd) measured by echocardiography decreased significantly (LVEDd: 50 ± 5 to 48 ± 5 mm, P < 0.01; LVESd: 33 ± 7 to 30 ± 6 mm, P < 0.01) in association with improvement of BNP level (39.9 ± 34.1 to 16.8 ± 10.3 pg/mL, P = 0.0001). In nine patients, whose VPBs were treated unsuccessfully by RFCA or that recurred, LV dimensions and BNP level did not change during the follow‐up period. Conclusion: Significant improvement in LV dimensions and serum BNP level appeared to indicate that RFCA of VPBs ameliorated occult cardiac dysfunction induced by frequent VPBs.
Electrocardiographic Characteristics of Repetitive Monomorphic Right Ventricular Tachycardia Originating Near the His‐Bundle
Authors: YAMAUCHI YASUTERU , AONUMA KAZUTAKA , TAKAHASHI ATSUSHI , SEKIGUCHI YUKIO , HACHIYA HITOSHI , YOKOYAMA YASUHIRO , KUMAGAI KOJI , NOGAMI AKIHIKO , IESAKA YOSHITO , ISOBE MITSUAKI 
Published: September 2005

Introduction: Most idiopathic nonreentrant ventricular tachycardia (VT) and ventricular premature contractions (VPCs) arise from the right or left ventricular outflow tract (OT). However, some right ventricular (RV) VT/VPCs originate near the His‐bundle region. The aim of this study was to investigate ECG characteristics of VT/VPCs originating near the His‐bundle in comparison with right ventricular outflow tract (RVOT)‐VT/VPCs. Methods and Results: Ninety RV‐VT/VPC patients underwent catheter mapping and radiofrequency ablation. ECG variables were compared between VT/VPCs originating from the RVOT and near the His‐bundle. Ten patients had foci near the His‐bundle (HIS group), with the His‐bundle local ventricular electrogram preceding the QRS onset by 15–35 msec (mean: 22 msec) and His‐bundle pacing produced a nearly identical ECG to clinical VT/VPCs. The HIS group R wave amplitude in the inferior leads (lead III: 1.0 ± 0.6 mV) was significantly lower than that of the RVOT group (1.7 ± 0.4 mV, P < 0.05). An R wave in aVL was present in 6 of 10 HIS group patients, while almost all RVOT group patients had a QS pattern in aVL. Lead I in HIS group exhibited significantly taller R wave amplitudes than RVOT group. HIS group QRS duration in the inferior leads was shorter than that of the RVOT group. Eight of 10 HIS group patients exhibited a QS pattern in lead V1 compared to 14 of 81 RVOT group patients. HIS group had larger R wave amplitudes in leads V5 and V6 than RVOT group. Conclusion: VT/VPCs originating near the His‐bundle have distinctive ECG characteristics. Knowledge of the characteristic QRS morphology may facilitate catheter mapping and successful ablation.
Modification of Ventricular Fibrillation Activation Patterns Induced by Local Stretching
Authors: CHORRO FRANCISCO J. , TRAPERO ISABEL , GUERRERO JUAN , SUCH LUIS M. , CANOVES JOAQUÍN , MAINAR LUIS , FERRERO ANGEL , BLASCO ESTRELLA , SANCHIS JUAN , MILLET JOSÉ , TORMOS ÁLVARO , BODÍ VICENTE , ALBEROLA ANTONIO 
Published: September 2005

Introduction: We hypothesize that local modifications in electrophysiological properties, when confined to zones of limited extent, induce few changes in the global activation process during ventricular fibrillation (VF). To test this hypothesis, we produced local electrophysiological modifications by stretching a circumscribed zone of the left ventricular wall in an experimental model of VF. Methods and Results: In 23 Langendorff‐perfused rabbit hearts frequency, time–frequency and time‐domain techniques were used to analyze the VF recordings obtained with two epicardial multiple electrodes before, during, and after local stretching produced with a left intraventricular device. Acute local stretching accelerated VF in the stretched zone reversibly and to a variable degree, depending on the magnitude of stretch and the time elapsed from its application. In the half time (5 minutes) of the analyzed period, a longitudinal lengthening of 12.1 ± 4.5% (vertical axis) and 11.8 ± 6.2% (horizontal axis) in the stretched zone produced an increase in the dominant frequency (DFr) (15.2 ± 1.9 versus 18.8 ± 2.5 Hz, P < 0.0001), a decrease in mean VV interval (63 ± 8 versus 53 ± 6 msec, P < 0.001), and an increase in the complexity of the activation maps—with more areas of conduction block and more breakthrough patterns (23% versus 37%, P < 0.01), without significant changes in the percentages of complete reentry patterns (9% versus 9%, ns). Simultaneously, in the nonstretched zone, no variations were observed in the DFr (15.2 ± 2.1 versus 15.3 ± 2.5 Hz, ns), mean VV intervals (66 ± 8 versus 65 ± 8 msec, ns), or types and percentages of maps with breakthrough (25% versus 20%, ns) or reentry patterns (12% versus 8%, ns). No significant correlation was observed between the DFr in the two zones (R = 0.24, P = 0.40). Conclusion: Local stretching increases the electrophysiological heterogeneity of myocardium and accelerates and increases the complexity of VF in the stretched area, without significantly modifying the occurrences of the types of VF activation patterns in the nonstretched zone.
Determinants of Recurrent Ventricular Arrhythmia or Death in 300 Consecutive Patients with Ischemic Heart Disease Who Experienced Aborted Sudden Death: Data from the Leiden Out‐of‐Hospital Cardiac Arrest Study
Authors: KIÈS PHILIPPINE , BOERSMA ERIC , BAX JEROEN J. , Van Der BURG ALIDA E. BORGER , BOOTSMA MARIANNE , Van ERVEN LIESELOT , Van Der WALL ERNST E. , SCHALIJ MARTIN J. 
Published: September 2005

Objective: Evaluation of the relation between clinical characteristics and incidence of recurrent ventricular arrhythmias (VAs) or death during long‐term follow‐up in a cohort of 300 consecutive ischemic heart disease (IHD) patients who had survived an episode of sudden cardiac arrest (SCA). Background: Survivors of life‐threatening VA are at high risk for recurrent events. Methods: A total of 300 consecutive survivors of SCA with IHD were included in a standardized screening and evaluation protocol. Multivariable Cox regression analysis was performed to determine the relation between clinical variables at baseline and the incidence of recurrent VA, all‐cause mortality and the composite of both (composite endpoint). Results: The presenting arrhythmia was VT in 156 (52%) patients and VF in 144 (48%) patients. Revascularization was performed in 78 (26%) patients and an ICD was implanted in 216 (72%) patients. During follow‐up (mean 30 ± 21 months) 37 (12%) patients died and 88 (29%) patients experienced a recurrence. Advanced age (adjusted hazard ratio (HR) 2.0; 1.2–3.3), history of heart failure (HR 1.8; 1.2–2.6), and amiodarone use (HR 3.1; 2.1–4.6) were independent predictors for the composite endpoint. VT as presenting arrhythmia was an independent predictor for all‐cause mortality only (HR 2.4; 1.2–4.8). A decreased risk of recurrences was determined by beta‐blocker use (HR 0.5; 0.4–0.8) and coronary revascularization (HR 0.3; 0.2–0.6). Conclusion: In a cohort of 300 consecutive survivors of SCA the incidence of recurrent VA and death is dependant on patient age, history of heart failure, and use of amiodarone. In contrast, use of beta‐blockers and aggressive coronary revascularization improve the outcome.
Wave Similarity Mapping Shows the Spatiotemporal Distribution of Fibrillatory Wave Complexity in the Human Right Atrium During Paroxysmal and Chronic Atrial Fibrillation
Authors: RAVELLI FLAVIA , FAES LUCA , SANDRINI LUCA , GAITA FIORENZO , ANTOLINI RENZO , SCAGLIONE MARCO , NOLLO GIANDOMENICO 
Published: September 2005

Introduction: The complexity of waveforms during atrial fibrillation may reflect critical activation patterns for the arrhythmia perpetuation. In this study, we introduce a novel concept of map, based on the analysis of the wave morphology, which gives a direct evidence in the human right atrium on the spatiotemporal distribution of fibrillatory wave complexity in paroxysmal (PAF) and chronic (CAF) atrial fibrillation. Methods and Results: Electrograms were recorded from a 64‐electrode catheter in the right atrium of 15 patients during PAF (n = 8) and CAF (n = 7). Wave similarity maps were constructed by calculating the degree of morphological similarity of activation waves (S) at each atrial site and by following its temporal evolution. During PAF the spatiotemporal distribution of the waveforms was highly consistent across the subjects and was determined by the anatomic location. Wave similarity maps showed the existence of an extended area with low similarity index, which covered the low posteroseptal atrium (S = 0.28 ± 0.09) and the septal region (S = 0.22 ± 0.04), and the presence of a large tongue with high similarity index, which penetrated the lateral wall (S = 0.55 ± 0.08) starting from the high anterolateral atrium (S = 0.54 ± 0.06). A completely different spatiotemporal pattern was seen during CAF. No distinct regions with different similarity indexes were recognized, but a uniformly distributed low similarity index (S = 0.27 ± 0.07) was found. The spatial pattern was highly stable in time with fluctuations of S < 0.04. Conclusion: Quantification of the spatiotemporal distribution of fibrillatory wave complexity is feasible in humans by wave similarity mapping. Anatomic anchoring of waveforms during PAF and pattern destruction during CAF was determined.
Transvenous Cryoablation Reduces Platelet Activation During Pulmonary Vein Ablation Compared with Radiofrequency Energy in Patients with Atrial Fibrillation
Authors: TSE HUNG‐FAT , KWONG YOK‐LAM , LAU CHU‐PAK 
Published: September 2005

Background: Radiofrequency (RF) ablation procedures for atrial fibrillation (AF) are associated with potential risks of thromboembolism, which may be minimized by the use of cryoablation that preserves the integrity of endocardium. The objective of this study was to compare the thrombogenic potential of transvenous cryoablation versus RF ablation during pulmonary vein (PV) isolation. Methods and Results: Thirty consecutive patients with paroxysmal AF were randomized to undergo segmental PV isolation procedure using 4‐mm tip RF ablation (n = 15) or cryoablation (CryoCor, San Diego, CA, USA) (n = 15). Blood samples were drawn after sheath insertion (baseline), after transseptal puncture, before ablation (after heparin administration), and after isolation of a superior PV. Activation of coagulation was measured with plasma levels of prothrombin fragment 1 + 2 (F1 + 2) and thrombin‐antithrombin III complex (TAT), and platelets by plasma level of β‐thromboglobulin (β‐TG) and flow cytometric enumerating of P‐selectin (CD62)‐positive platelets. In both groups, the plasma level of β‐TG, F1 + 2, and TAT were elevated after sheath insertion. The percentage changes in plasma level of β‐TG, F1 + 2, and TAT and CD41/62‐positive platelets from baseline after transseptal puncture and before ablation were similar (P > 0.05). However, the percentage changes in CD62‐positive platelets from baseline were significantly higher in patients treated with RF ablation (82 ± 20%) than with cryoablation (22 ± 14%, P = 0.02), although their plasma levels of β‐TG, F1 + 2, and TAT were not different (P > 0.05). Conclusions: Significant platelet and coagulation activations were observed during PV ablation procedures, and heparin administration only prevented activation of coagulation but not platelets. Persistent platelets activation was observed during RF energy application, but not during cryoablation.
Relationship between bleeding on probing and periodontal disease progression in community‐dwelling older adults
Authors: Rahardjo A. , Yoshihara A. , Amarasena N. , Ogawa H. , Nakashima K. , Miyazaki H. 
Published: October 2005

AbstractObjective: The main objective of this study was to determine the relationship between bleeding on probing (BOP) and periodontal disease progression in community‐dwelling older adults.Methods: A 3‐year longitudinal study was carried out in 229 non‐smoking healthy older adults aged 70 years. Using pressure‐controlled periodontal probes, BOP, pocket depth and attachment level at 13,289 sites were measured annually. Periodontal disease progression was defined as an increase in attachment loss of 3 mm from the baseline to the final examination. The backward stepwise logistic regression analysis was performed to assess the relationship between the total number of sites with BOP in the four examinations and periodontal progression.Results: Logistic regression analysis showed that the odds ratios of BOP frequency for periodontal disease progression ranged from 1.4 to 6.2 after controlling for pocket depth 4 mm at baseline, number of missing teeth, jaw type and tooth site.Conclusion: Increasing frequencies of bleeding might increase the probability of periodontal disease progression in community‐dwelling older adults.