First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions.

We report results of Λ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014 GeV electron beam. These results represent the first measurements of the Λ multiplicity ratio and transverse momentum broadening as a function of the energy fraction (z) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high z and an enhancement at low z. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high z. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons.

Observation of Azimuth-Dependent Suppression of Hadron Pairs in Electron Scattering off Nuclei.

We present the first measurement of dihadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the gibuu model, which suggests that hadrons form near the nuclear surface and undergo multiple scattering in nuclei.These results show that angular correlation studies can open a new way to elucidate how hadrons form and interact inside nuclei.

Photoproduction of the f_{2}(1270) Meson Using the CLAS Detector.

The quark structure of the f_{2}(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq[over ¯]) resonance with quantum numbers J^{PC}=2^{++}. Recently, it was proposed that the f_{2}(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρ→π^{+}π^{-}, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γp→π^{0}π^{0}p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f_{2}(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.

Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs.

A first measurement of the longitudinal beam spin asymmetry A_{LU} in the semi-inclusive electroproduction of pairs of charged pions is reported. A_{LU} is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498-GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the A_{LU}^{sinϕ_{R}} moments are extracted for the kinematic variables of interest in the valence quark region. The understanding of dihadron production is essential for the interpretation of observables in single-hadron production in semi-inclusive DIS, and pioneering measurements of single-spin asymmetries in dihadron production open a new avenue in studies of QCD dynamics.

Improved Λp Elastic Scattering Cross Sections between 0.9 and 2.0 GeV/c as a Main Ingredient of the Neutron Star Equation of State.

Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state. Yet, compared to other elastic scattering processes, there is very little data on Λ-N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the Λp→Λp elastic scattering cross section in the incident Λ momentum range 0.9-2.0 GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments.

Extraction of Beam-Spin Asymmetries from the Hard Exclusive π

We have measured beam-spin asymmetries to extract the sinϕ moment A_{LU}^{sinϕ} from the hard exclusive e[over →]p→e^{'}nπ^{+} reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center of mass. The A_{LU}^{sinϕ} moment has been measured up to 6.6 GeV^{2} in -t, covering the kinematic regimes of generalized parton distributions (GPD) and baryon-to-meson transition distribution amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found A_{LU}^{sinϕ} to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

Signaling pathways have an inherent need for noise to acquire information.

BACKGROUND: All living systems acquire information about their environment. At the cellular level, they do so through signaling pathways. Such pathways rely on reversible binding interactions between molecules that detect and transmit the presence of an extracellular cue or signal to the cell's interior. These interactions are inherently stochastic and thus noisy. On the one hand, noise can cause a signaling pathway to produce the same response for different stimuli, which reduces the amount of information a pathway acquires. On the other hand, in processes such as stochastic resonance, noise can improve the detection of weak stimuli and thus the acquisition of information. It is not clear whether the kinetic parameters that determine a pathway's operation cause noise to reduce or increase the acquisition of information. RESULTS: We analyze how the kinetic properties of the reversible binding interactions used by signaling pathways affect the relationship between noise, the response to a signal, and information acquisition. Our results show that, under a wide range of biologically sensible parameter values, a noisy dynamic of reversible binding interactions is necessary to produce distinct responses to different stimuli. As a consequence, noise is indispensable for the acquisition of information in signaling pathways. CONCLUSIONS: Our observations go beyond previous work by showing that noise plays a positive role in signaling pathways, demonstrating that noise is essential when such pathways acquire information.

Hairy root transformation of Brassica rapa with bacterial halogenase genes and regeneration to adult plants to modify production of indolic compounds.

During the last years halogenated compounds have drawn a lot of attention. Metabolites with one or more halogen atoms are often more active than their non-halogenated derivatives like indole-3-acetic acid (IAA) and 4-Cl-IAA. Within this work, bacterial flavin-dependent tryptophan halogenase genes were inserted into Brassica rapa ssp. pekinensis (Chinese cabbage) with the aim to produce novel halogenated indole compounds. It was investigated which tryptophan-derived indole metabolites, such as indole glucosinolates or potential degradation products can be synthesized by the transgenic root cultures. In vivo and in vitro activity of halogenases heterologously produced was shown and the production of chlorinated tryptophan in transgenic root lines was confirmed. Furthermore, chlorinated indole-3-acetonitrile (Cl-IAN) was detected. Other tryptophan-derived indole metabolites, such as IAA or indole glucosinolates were not found in the transgenic roots in a chlorinated form. The influence of altered growth conditions on the amount of produced chlorinated compounds was evaluated. We found an increase in Cl-IAN production at low temperatures (8 °C), but otherwise no significant changes were observed. Furthermore, we were able to regenerate the wild type and transgenic root cultures to adult plants, of which the latter still produced chlorinated metabolites. Therefore, we conclude that the genetic information had been stably integrated. The transgenic plants showed a slightly altered phenotype compared to plants grown from seeds since they also still expressed the rol genes. By this approach we were able to generate various stably transformed plant materials from which it was possible to isolate chlorinated tryptophan and Cl-IAN.

First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton.

We report on the measurement of the γp→J/ψp cross section from E_{γ}=11.8 GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39 GeV^{-2} at 10.7 GeV average energy. The LHCb pentaquark candidates P_{c}^{+} can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(P_{c}^{+}→J/ψp) and cross sections σ(γp→P_{c}^{+})×B(P_{c}^{+}→J/ψp).

Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering.

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering off a proton bound in ^{4}He. The data used here were accumulated using a 6 GeV longitudinally polarized electron beam incident on a pressurized ^{4}He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle (ϕ) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The Q^{2}, x_{B}, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20% to 40%, indicating possible medium modification of its partonic structure.

Direct Observation of Proton-Neutron Short-Range Correlation Dominance in Heavy Nuclei.

We measured the triple coincidence A(e,e^{'}np) and A(e,e^{'}pp) reactions on carbon, aluminum, iron, and lead targets at Q^{2}>1.5 (GeV/c)^{2}, x_{B}>1.1 and missing momentum >400 MeV/c. This was the first direct measurement of both proton-proton (pp) and neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all measured nuclei, the average proton-proton (pp) to neutron-proton (np) reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for single-charge exchange effects decreased the SRC pairs ratio to ∼3%, which is lower than previous results. Comparisons to theoretical generalized contact formalism (GCF) cross-section calculations show good agreement using both phenomenological and chiral nucleon-nucleon potentials, favoring a lower pp to np pair ratio. The ability of the GCF calculation to describe the experimental data using either phenomenological or chiral potentials suggests possible reduction of scale and scheme dependence in cross-section ratios. Our results also support the high-resolution description of high-momentum states being predominantly due to nucleons in SRC pairs.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the A(e,e

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.

Measurement of the Q

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9 GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02 GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

A novel technique for the assessment of total liver blood flow in pregnancy: interrater and intrarater agreements.

OBJECTIVE: To improve the technique for hepatic blood flow examination, with the objective of investigating the role for Doppler flowmetry of the liver in monitoring pregnant females with pre-eclampsia. METHODS: Two physicians independently examined a group of 50 healthy pregnant females. The main difference in the proposed technique is the measurement of the vessel cross-sectional area and the adjustment of the Doppler samples according to the diameter of each vessel. The portal vein was studied by using two approaches: in the epigastrium, to measure the diameter, and in the intercostal, for Doppler sample collection. The common hepatic artery was studied by using the epigastric approach. The average of three measurements of each vessel, in each subject, with intrarater and interrater agreements, was compared. RESULTS: The intraclass correlation coefficient for the intrarater flow measurements of the hepatic artery and portal vein ranged from 0.98 to 0.99 (p < 0.0001). The intraclass correlation coefficients for the interrater flow measurements was 0.93 for the flow of the portal vein (p < 0.0001), 0.94 for the flow of the hepatic artery (p < 0.0001) and 0.96 for the measurement of the portal vein diameter (p < 0.0001). CONCLUSION: The new technique for evaluation of blood flow to the liver displayed excellent reproducibility, possibly because of the adjustment of the Doppler samples according to the diameter of each vessel. Advances in knowledge: This approach will add reliability to the method. It opens a vast field of investigation given the importance of liver vascular lesions in pre-eclampsia.

Characterization of the Aminotransferase ThdN from Thienodolin Biosynthesis in Streptomyces albogriseolus.

In Streptomyces albogriseolus the indolethiophen alkaloid thienodolin is derived from tryptophan. The first step in thienodolin biosynthesis is the regioselective chlorination of tryptophan in the 6-position of the indole ring. The second step is catalyzed by the aminotransferase ThdN. ThdN shows sequence homology (up to 69 % similarity) with known pyridoxal 5'-phosphate-dependent aminotransferases of the aspartate aminotransferase family from Gram-positive bacteria. thdN was heterologously expressed in Pseudomonas fluorescens, and the enzyme was purified by nickel-affinity chromatography. ThdN is a homodimeric enzyme with a mass of 90 600 kDa and catalyzes the conversion of l-tryptophan and a number of chlorinated and brominated l-tryptophans. The lowest KM values were found for 6-bromo- and 6-chlorotryptophan (40 and 66 µm, respectively). For l-tryptophan it was 454 µm, which explains why thienodolin is the major product and dechlorothienodolin is only a minor component. The turnover number (kcat ) for 7-chlorotryptophan (128 min-1 ) was higher than that for the natural substrate 6-chlorotryptophan (88 min-1 ).

Alternativa de intervención en la infección de la bolsa del marcapaso permanente / Alternative to surgical intervention in permanent pacemaker pocket infection

Fundamento: actualmente la infección de la bolsa del marcapasos permanente se trata mediante técnicas percutáneas o cirugía cardíaca a cielo abierto, la primera no es una práctica habitual y la segunda muchas veces está contraindicada.Objetivo: valorar la respuesta a la aplicación de una nueva alternativa de intervención en la infección de la bolsa del marcapasos.Métodos: se realizó un estudio de intervención, cuasiexperimental modalidad grupo único. El universo estuvo constituido por 28 pacientes que ingresaron con el diagnóstico de infección de la bolsa del marcapasos, posterior a los seis meses de realizado la implantación, en el Hospital Universitario Manuel Ascunce Domenech, de 2008 a enero 2015. La información obtenida se procesó mediante el programa estadístico SPSS-19.0 para Windows y estadística descriptiva con distribución de frecuencia y porcientos. Los resultados del estudio se expusieron en tablas.Resultados: 28 pacientes fueron sometidos a la nueva alternativa de intervención, con un rango de edad entre 51 y 93 años, con una media de 78, 5 años. Predominó el sexo femenino, 17 pacientes (60, 7 porciento). La necrosis por presión en nueve pacientes, 32, 1 porciento, fue el mayor factor predisponente; la infección tuvo mayor relación con el cambio del marcapasos, 26 pacientes (92, 9 porciento); así como la necrosis séptica 20 pacientes (71, 4 porciento) fue la forma clínica de presentación más incidente. El staphylococcus epidermidis se aislóen 11 pacientes (39, 3 porciento). No hubo complicaciones durante el acto quirúrgico y los 28 pacientes (100 porciento) sometidos a la intervención cumplieron los criterios de curación.Conclusión: la alternativa de intervención en la infección de la bolsa del marcapasos propuesta, es una opción segura y viable en el tratamiento de estos pacientes, y a la vez una variante en sustitución de las técnicas percutáneas o cirugía abierta.(AU)

Background: nowadays, permanent pacemaker pocket infection is treated with percutaneous techniques or open heart surgery. The former is not a usual practice and the latter is mostly contraindicated.Objective: to assess the response to the application of a new alternative in surgery of the pacemaker pocket infection.Methods: a unique group quasi-experimental intervention study was conducted after six years of the implantation, at the Manuel Ascunce Domenech Hospital, from January 2008 to January 2015. The universe was composed of 28 patients who were admitted and diagnosed with pacemaker pocket infection.The information obtained was processed through SPSS-19.0 statistical program for Windows, and descriptive statistics with distribution of frequency and percentage. The results of the study were reported in tables.Results: the 51 to 93 age group of twenty-eight patients went through the new alternative of intervention, with an average of 78, 5 years old. Female sex was predominant, 17 patients (60, 7 percent). Pressure necrosis in nine patients, 32, 1percent, was the most predisposing factor. The infection was more related to the change of pacemaker, 26 patients (92, 9 percent), and septic necrosis (20 patients, 71, 4 percent) was the most influential clinical presentation form. The staphylococcus epidermidis was isolated in 11 patients (39, 3 percent). There were no complications during the surgical procedure and the 28 patients (100 percent) who underwent surgery stuck to the treatment criteria.Conclusion: the proposed alternative of intervention in pacemaker pocket infection is a save and viable option in the treatment of these patients, as well as a variant in the substitution of percutaneous techniques or open surgery.(AU)

Registro de implante de marcapasos: trece años de experiencia / Pacemaker implantation record: a thirteen-year experience

Fundamento: los avances en los diseños de los marcapasos y su simplificación en la técnica de implantación, han permitido que la estimulación eléctrica del corazón sea una práctica habitual en gran número de hospitales provinciales.Objetivo: describir los resultados de la implantación de marcapasos permanente.Métodos: se realizó un estudio descriptivo, retrospectivo a un universo de 2 590 pacientes, a quienes se les implantó o cambió los marcapasos permanentes, en el Hospital Universitario Manuel Ascunce Domenech, desde enero de 2002 hasta enero de 2015. La información obtenida se procesó mediante el programa estadístico SPSS-19.0 para Windows y estadística descriptiva con distribución de frecuencia y porcientos. Los resultados del estudio se expusieron en tablas y gráficos.Resultados: 2 590 pacientes fueron sometidos al proceder (primoimplante 71, 5 porciento y recambio 28, 5 porciento). El rango de edad fluctúo entre 14 y 102 años, con un promedio de edad de 74, 6. La vía de abordaje para introducir el electrodo que predominó fue la disección de la vena cefálica (1 905 eletrodos-90, 1 porciento). EL síncope en 969 (52, 3 porciento) de los casos, el bloqueo auriculoventricular en 1 219 (65, 8 porciento) y la posible fibrosis del sistema de conducción en 897 (48, 4 porciento), fueron las principales causas del motivo del implante. El modo de estimulación VVI se utilizó en 1 714 enfermos (72, 3 porciento) y el DDD en 384 (14, 8 porciemto). La principal causa del recambio del dispositivo fue el agotamiento por fin de vida de la batería en 692 casos (93, 9 porciento). Las complicaciones relacionadas con el proceder fueron en 124 pacientes (4, 8 porciento).Conclusiones: debe aumentarse el consumo de marcapasos estimado por millón de habitantes en la provincia de Camagüey, así como el modo de estimulación DDD. La implantación es segura en esta provincia.(AU)

Background: breakthroughs in the design of pacemakers and their simplification in implantation techniques allow the electric stimulation of the heart to be a usual practice in many provincial hospitals.Objective: to describe the results of permanent pacemaker implantation.Methods: a retrospective and descriptive review between January, 2002 and 2015 was performed. The universe included 2 590 patients, who had their permanent pacemakers implanted or changed at Manuel Ascunce Domenech Hospital. The information obtained was processed with SPSS-19.0 statistical program for Windows and descriptive statistic with frequency distribution and percentage. The results of the review were shown in tables and graphs.Results: 2 590 patients underwent the procedure (first implantation 71, 5 percent and reimplantation 28, 5 percent). Age range fluctuated between 14 and 102 years, with an age average of 74, 6. The dissection of the cephalic vein (1905 electrodes- 90, 1 percent) was the predominant approach to introduce the electrode. Syncope in 969 (52, 3 percent) of the cases, atrioventricular block in 1 219 (65, 8 percent), and the possible fibrosis of the heart´s conducting system in 897 (48, 4 percent) were the main causes of the implantation. VVI stimulation mode was used in 1 714 patients (72, 3 percent) and DDD in 384 (14, 8 percent). The main cause of the device reimplantation was dead batteries in 692 cases (93, 9 percent). Complications related to the procedure arose in 124 patients (4, 8 percent).Conclusions: consumption of pacemakers estimated per million inhabitants in the province of Camaguey should be increased along with DDD pacing mode. The implantation is safe in this province.(AU)

Registro de implante de marcapasos: trece años de experiencia / Pacemaker implantation record: a thirteen-year experience

Fundamento: los avances en los diseños de los marcapasos y su simplificación en la técnica de implantación, han permitido que la estimulación eléctrica del corazón sea una práctica habitual en gran número de hospitales provinciales. Objetivo: describir los resultados de la implantación de marcapasos permanente. Métodos: se realizó un estudio descriptivo, retrospectivo a un universo de 2 590 pacientes, a quienes se les implantó o cambió los marcapasos permanentes, en el Hospital Universitario Manuel Ascunce Domenech, desde enero de 2002 hasta enero de 2015. La información obtenida se procesó mediante el programa estadístico SPSS-19.0 para Windows y estadística descriptiva con distribución de frecuencia y porcientos. Los resultados del estudio se expusieron en tablas y gráficos. Resultados: 2 590 pacientes fueron sometidos al proceder (primoimplante 71, 5 % y recambio 28, 5 %). El rango de edad fluctúo entre 14 y 102 años, con un promedio de edad de 74, 6. La vía de abordaje para introducir el electrodo que predominó fue la disección de la vena cefálica (1 905 eletrodos-90, 1 %). EL síncope en 969 (52, 3 %) de los casos, el bloqueo auriculoventricular en 1 219 (65, 8 %) y la posible fibrosis del sistema de conducción en 897 (48, 4 %), fueron las principales causas del motivo del implante. El modo de estimulación VVI se utilizó en 1 714 enfermos (72, 3 %) y el DDD en 384 (14, 8 %). La principal causa del recambio del dispositivo fue el agotamiento por fin de vida de la batería en 692 casos (93, 9 %). Las complicaciones relacionadas con el proceder fueron en 124 pacientes (4, 8 %). Conclusiones: debe aumentarse el consumo de marcapasos estimado por millón de habitantes en la provincia de Camagüey, así como el modo de estimulación DDD. La implantación es segura en esta provincia.

Background: breakthroughs in the design of pacemakers and their simplification in implantation techniques allow the electric stimulation of the heart to be a usual practice in many provincial hospitals. Objective: to describe the results of permanent pacemaker implantation. Methods: a retrospective and descriptive review between January, 2002 and 2015 was performed. The universe included 2 590 patients, who had their permanent pacemakers implanted or changed at Manuel Ascunce Domenech Hospital. The information obtained was processed with SPSS-19.0 statistical program for Windows and descriptive statistic with frequency distribution and percentage. The results of the review were shown in tables and graphs. Results: 2 590 patients underwent the procedure (first implantation 71, 5 % and reimplantation 28, 5 %). Age range fluctuated between 14 and 102 years, with an age average of 74, 6. The dissection of the cephalic vein (1905 electrodes- 90, 1 %) was the predominant approach to introduce the electrode. Syncope in 969 (52, 3 %) of the cases, atrioventricular block in 1 219 (65, 8 %), and the possible fibrosis of the heart´s conducting system in 897 (48, 4 %) were the main causes of the implantation. VVI stimulation mode was used in 1 714 patients (72, 3 %) and DDD in 384 (14, 8 %). The main cause of the device reimplantation was dead batteries in 692 cases (93, 9 %). Complications related to the procedure arose in 124 patients (4, 8 %). Conclusions: consumption of pacemakers estimated per million inhabitants in the province of Camaguey should be increased along with DDD pacing mode. The implantation is safe in this province.

Alternativa de intervención en la infección de la bolsa del marcapaso permanente / Alternative to surgical intervention in permanent pacemaker pocket infection

Fundamento: actualmente la infección de la bolsa del marcapasos permanente se trata mediante técnicas percutáneas o cirugía cardíaca a cielo abierto, la primera no es una práctica habitual y la segunda muchas veces está contraindicada. Objetivo: valorar la respuesta a la aplicación de una nueva alternativa de intervención en la infección de la bolsa del marcapasos. Métodos: se realizó un estudio de intervención, cuasiexperimental modalidad grupo único. El universo estuvo constituido por 28 pacientes que ingresaron con el diagnóstico de infección de la bolsa del marcapasos, posterior a los seis meses de realizado la implantación, en el Hospital Universitario Manuel Ascunce Domenech, de 2008 a enero 2015. La información obtenida se procesó mediante el programa estadístico SPSS-19.0 para Windows y estadística descriptiva con distribución de frecuencia y porcientos. Los resultados del estudio se expusieron en tablas. Resultados: 28 pacientes fueron sometidos a la nueva alternativa de intervención, con un rango de edad entre 51 y 93 años, con una media de 78, 5 años. Predominó el sexo femenino, 17 pacientes (60, 7 %). La necrosis por presión en nueve pacientes, 32, 1 %, fue el mayor factor predisponente; la infección tuvo mayor relación con el cambio del marcapasos, 26 pacientes (92, 9 %); así como la necrosis séptica 20 pacientes (71, 4 %) fue la forma clínica de presentación más incidente. El staphylococcus epidermidis se aislóen 11 pacientes (39, 3 %). No hubo complicaciones durante el acto quirúrgico y los 28 pacientes (100 %) sometidos a la intervención cumplieron los criterios de curación. Conclusión: la alternativa de intervención en la infección de la bolsa del marcapasos propuesta, es una opción segura y viable en el tratamiento de estos pacientes, y a la vez una variante en sustitución de las técnicas percutáneas o cirugía abierta.

Background: nowadays, permanent pacemaker pocket infection is treated with percutaneous techniques or open heart surgery. The former is not a usual practice and the latter is mostly contraindicated. Objective: to assess the response to the application of a new alternative in surgery of the pacemaker pocket infection. Methods: a unique group quasi-experimental intervention study was conducted after six years of the implantation, at the Manuel Ascunce Domenech Hospital, from January 2008 to January 2015. The universe was composed of 28 patients who were admitted and diagnosed with pacemaker pocket infection. The information obtained was processed through SPSS-19.0 statistical program for Windows, and descriptive statistics with distribution of frequency and percentage. The results of the study were reported in tables. Results: the 51 to 93 age group of twenty-eight patients went through the new alternative of intervention, with an average of 78, 5 years old. Female sex was predominant, 17 patients (60, 7%). Pressure necrosis in nine patients, 32, 1%, was the most predisposing factor. The infection was more related to the change of pacemaker, 26 patients (92, 9%), and septic necrosis (20 patients, 71, 4%) was the most influential clinical presentation form. The staphylococcus epidermidis was isolated in 11 patients (39, 3%). There were no complications during the surgical procedure and the 28 patients (100%) who underwent surgery stuck to the treatment criteria. Conclusion: the proposed alternative of intervention in pacemaker pocket infection is a save and viable option in the treatment of these patients, as well as a variant in the substitution of percutaneous techniques or open surgery.