960-84 Ramdomized Prospective Comparison of Four Burst Pacing Algorithms for Spontaneous Ventricular Tachycardia

Burst antitachycardia pacing (ATP) is higly efficacious for termination of monomorphic ventricular tachycardia (MVT). Since several pacing sequences are usually programmed as a single therapy. optimal programming is presently unknown. In 40 patients (P) with MVT and a 3rd generation AICD, 4 burst ATP were prospectively compared (as afirst single ATP) during followup in a randomized design crossing over every 2–3 months. Burst ATP modes (A to D) were defined by pacing cycle length (PCL, as % of VTCL) and number of beats (No B) (Table). A second ATP zone was programmed in a non selected way in all patientsResults (Table)374 episodes (317 considered MVT) received ATP therapies in 23 patients. RR intervals could be retrieved for MVT-CL analysis in 168 episodes. Succes rate of combined first (randomized) and second (non selected) therapies was 92%. Acceleration rate estimation was 2%.TherapyABCDglobalpPCL/No B91/781/791/1581/15AllVT68%46%85%61%69%<0.001VTCL < 350*82%14%44%38%47%0.03VTCL> 350°73%100%91%86%90%ns*Cl < 350: group of Mvr with Cl < 350ms°Cl > 350: Mvr with Cl > 350msConclusions1. Efficacy of the tested burst pacing modes differs significantly, at least in fast VT. 2. Contrary to what could be expected. “less agressive” bursts seem to be more efficacious, even in fast VT

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA)

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 ◦C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 ◦C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients

Iron-dependent oxygen free radical generation in plants subjected to environmental stress: toxicity and antioxidant protection

24 Pags. The definitive version, with Figs. and Tabls., is available at: http://link.springer.com/journal/11104Iron has a pivotal and dual role in free radical chemistry in all organisms. On the one hand, free Fe can participate in Fenton reactions and catalyze (‘catalytic Fe’) the generation of hydroxyl radical and other toxic oxygen species. On the other hand, Fe is a constituent of the antioxidant enzymes catalase, ascorbate peroxidase, guaiacol peroxidase, and ferro-superoxide dismutase. Protein Fe is Fenton inactive but can be released from proteins upon attack by activated oxygen. Healthy, unstressed plants avoid the interaction of catalytic Fe and peroxides by disposing of Fe in vacuoles and apoplast, by sequestering Fe in ferritin, and by having high levels of antioxidant enzymes and metabolites in most subcellular compartments. However, when plants are exposed to a variety of adverse conditions, including chilling, high light, drought and paraquat, oxidative stress ensues due primarily to the decrease in antioxidant defenses but also to the increase in free radical production mediated by catalytic Fe. The latter accumulates in many stressed plant tissues. Oxidative stress may lead to metabolic dysfunction and ultimately to plant cell death, so it needs to be estimated conveniently by quantifying the oxidation products of lipids (malondialdehyde and other cytotoxic aldehydes), proteins (total carbonyls, methionine sulfoxide, 2-oxohistidine), and DNA (8-hydroxyguanine, 5-hydroxycytosine). Protein oxidation appears to be a more sensitive and precocious marker than is lipid peroxidation, and DNA damage may also prove to be a useful marker for stress studies in plants.The work reported from our laboratory was funded by grants PB92-0058 and PB95-0091 from the Ministerio de Educación y Cultura (Spain).Peer reviewe

Structure and function of leghemoglobins

Legemoglobin (Lb) is a myoglobin-like protein of about 16KDa, which occurs in legume root nodules at very high concentrations. Usually the heme moiety is synthesized by th bacteroids but mitochondria may provide also heme for Lb when bacteria are defective in heme production or perhaps when Lb is produced in unifected cells of nodules. Lb plays and essential role in the nitrogen fixation process, by providing oxygen to the bacteroids at a low, but constant, concentration, which allows for simultaneous bacteroid respiration and nitrogenase activity. Lb must be in the reduced, ferrous state to carry oxygen. Several factors within the nodules are conducive for Lb oxidation to its ferric, inactive form. During these inactivation reactions free radicals are generated. However, healthy nodules contain around 80% of ferrous Lb and 20% of oxyferrous Lb, but not ferric Lb, which indicates that mechanisms exist in the nodules to maintain Lb reduced; these are the enzyme ferric Lb reductase and free flavins Lb degradation is a largely unknown process, but several intermediates with modified hemes, presumably by oxidative attack, have been encountered, including modified Lbam, choleglobin, and biliverdin.The original work reported here has been financed by grants PCB-10/90 (CONAI-DGA), AGR91-0857-C02-02 (CICYT), and PB92-0058 (DGICYT).Peer reviewe

Polipéptido con actividad homoglutatión sintetasa

Referencia OEPM: P200101494.-- Fecha de solicitud: 28/06/2001.-- Titulares: Consejo Superior de Investigaciones Científicas (CSIC).La presente invención describe la obtención de una nueva proteína con actividad homoglutatión sintetasa. La presente invención incluye la secuencia de nucleótidos (SEQ ID NO 1) que codifica esta proteína, así como la secuencia de aminoácidos de la misma (SEQ ID NO 2), el uso de dicha secuencia de nucleótidos en el desarrollo de construcciones génicas, la expresión de la misma en células huésped y el uso de esta enzima en el campo de la síntesis de homoglutatión.Peer reviewe

Registro Español de Desfibrilador Automático Implantable. III Informe Oficial (2006)

Se presentan los resultados del Registro Español de Desfibrilador Automático Implantable del año 2006 elaborado por el Grupo de Trabajo de Desfibrilador Automático Implantable de la Sección de Electrofisiología y Arritmias de la Sociedad Española de Cardiología. Métodos: Se envió a la Sociedad Española de Cardiología la hoja de recogida de datos cumplimentada de forma voluntaria por cada equipo implantador. La recogida fue prospectiva en el 91,8% de los implantes. Resultados: El número de implantes comunicados fue de 2.679 (el 86,6% del total de implantes estimado). El número de implantes/millón de habitantes comunicados fue 60 y el estimado, 69. Los primoimplantes fueron el 80%. La mayor parte de los desfibriladores automáticos implantables se implantaron en varones con una media de edad de 61,5 ± 14 años, con disfunción ventricular izquierda grave o moderada-grave y en clase funcional II o I. La cardiopatía más frecuente fue la isquémica, seguida de la dilatada. Por primera vez, las indicaciones por prevención primaria constituyen la mitad de las realizadas en los primoimplantes, con un crecimiento importante en pacientes con cardiopatía isquémica y miocardiopatía dilatada. Ha continuado aumentando el número de desfibriladores automáticos implantables con terapia de resincronización cardíaca implantados, que constituyeron el 28,6% del total. En torno al 70% de los implantes se llevaron a cabo en el laboratorio de electrofisiología y por electrofisiólogos, cifra que se ha mantenido estable desde el pasado año. La incidencia de complicaciones durante el implante fue muy baja. Conclusiones: El Registro Español de Desfibrilador Automático Implantable del año 2006 recoge información de más del 86% de los implantes totales de desfibrilador automático implantable que se realizan en España. La mitad de los primoimplantes llevados a cabo se indicaron con fines de prevención primaria

Drought induces oxidative stress in pea plants

23 Pags.- 2 Tabls. The definitive version, with Figs., is available at: http://link.springer.com/journal/425Pea (Pisum sativum L. cv. Frilene) plants subjected to drought (leaf water potential of ≈-1.3 MPa) showed major reductions in photosynthesis (78‰), transpiration (83‰), and glycolate oxidase (EC 1.1.3.1) activity (44‰), and minor reductions (≈18‰) in the contents of chlorophyll a, carotenoids, and soluble protein. Water stress also led to pronounced decreases (72–85‰) in the activities of catalase (EC 1.11.1.6), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2), but resulted in the increase (32–42‰) of non-specific peroxidase (EC 1.11.1.7) and superoxide dismutase (EC 1.15.1.1). Ascorbate peroxidase (EC 1.11.1.11) and monodehydroascorbate reductase (EC 1.6.5.4) activities decreased only by 15‰ and the two enzymes acted in a cyclic manner to remove H2O2, which did not accumulate in stressed leaves. Drought had no effect on the levels of ascorbate and oxidized glutathione in leaves, but caused a 25‰ decrease in the content of reduced glutathione and a 67‰ increase in that of vitamin E. In leaves, average concentrations of catalytic Fe, i.e. Fe capable of catalyzing free-radical generation by redox cycling, were estimated as 0.7 to 7 μM (well-watered plants, depending on age) and 16 μM (water-stressed plants); those of catalytic Cu were ≈4.5 μM and 18 μM, respectively. Oxidation of lipids and proteins from leaves was enhanced two- to threefold under stress conditions and both processes were highly correlated. Fenton systems composed of the purported concentrations of ascorbate, H2O2, and catalytic metal ions in leaves produced hydroxyl radicals, peroxidized membrane lipids, and oxidized leaf proteins. It is proposed that augmented levels and decompartmentation of catalytic metals occurring during water stress are responsible for the oxidative damage observed in vivo.J.F.M., I. I., and S.F. were the recipients of predoctoral fellowships from the Comunidades Autónomas de Aragón, País Vasco, and Navarra, respectively. R.V.K. thanks the U.S. Department of Agriculture (grant 91-37305-6705) for travel support. This work was financed by grants from the Comisión Interministerial de Ciencia y Tecnología (AGR-91-0857-C02 to P.A. and M.B.) and Dirección General de Investigación Científica y Técnica (PB92-0058 to M.B).Peer reviewe

Reactive oxygen species and antioxidants in legume nodules

28 Pags.- 2 Figs. the definitive version is available at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291399-3054Reactive oxygen species are a ubiquitous danger for aerobic organisms. This risk is especially elevated in legume root nodules due to the strongly reducing conditions, the high rates of respiration, the tendency of leghemoglobin to autoxidize, the abundance of nonprotein Fe and the presence of several redox proteins that leak electrons to O(2). Consequently, nodules are particularly rich in both quantity and diversity of antioxidant defenses. These include enzymes such as superoxide dismutase (EC 1.15.1.1) and ascorbate peroxidase (EC 1.11.1.11) and metabolites such as ascorbate and thiol tripeptides. Nodule antioxidants have been the subject of intensive molecular, biochemical and functional studies that are reviewed here. The emerging theme is that antioxidants are especially critical for the protection and optimal functioning of N(2) fixation. We hypothesize that this protection occurs at least at two levels: the O(2) diffusion barrier in the nodule parenchyma (inner cortex) and the infected cells in the central zone.Work in the laboratory of M. B. was supported by grants PB98-0522, 2FD97-1101 and HB98-163 from Dirección General de Enseñanza Superior e Investigación Científica, Comisión Interministerial de Ciencia y Tecnología, and the European Union. Work in the laboratory of D. A. D. was supported by National Science Foundation grants DCB-8903254, IBN-9206453 and IBN-9507491.Peer Reviewe

Registro Español de Desfibrilador Automático Implantable. I Informe Oficial (años 2002–2004)

Se presentan los resultados del Registro Nacional de Desfibrilador Automático Implantable (DAI) en el periodo 2002-2004 elaborado por el Grupo de Trabajo de Desfibrilador Automático Implantable de la Sociedad Española de Cardiología. Material y método: Se elaboró una hoja de recogida de datos que fue cumplimentada prospectivamente y de forma voluntaria por cada equipo implantador y enviada a la Sociedad Española de Cardiología. Resultados: El número de implantes comunicados fue de 925, 1.046 y 1.414 en los años 2002, 2003 y 2004 que representan el 63, 59 y 67,5%, del total estimado de implantes, respectivamente. El número de implantes/millón de habitantes comunicados fue de 22, 24 y 33 y el estimado de 35, 41 y 49. El número de recambios aumentó del 20 al 30% entre 2002 y 2004. La mayor parte de los DAI se implantó en varones con 66 años de edad mediana, disfunción ventricular izquierda moderada o grave y en clase funcional II o I. La cardiopatía más frecuente fue la isquémica. Las principales indicaciones fueron taquicardia ventricular monomórfica sostenida y muerte súbita abortada, con un número creciente de indicaciones profilácticas. Cada vez se realizan más implantes en el laboratorio de electrofisiología y por electrofisiólogos. La proporción de DAI bicamerales se aproxima al 30% y la de DAI con resincronización al 15%. La incidencia de complicaciones durante el implante fue muy baja. Conclusiones: El Registro Nacional de DAI recoge una muestra representativa de los implantes de DAI que se llevan a cabo en nuestro país y una de las mayores publicadas