Electric Pulsation Research Articles

P380 THE REEL‘S SYNDROME : A RARE COMPLICATION AFTER PACEMAKER IMPLANTATION

Abstract We report the case of a 83–year–old male who underwent single chamber pacemaker implantation in another center for bradyarrhythmia (atrial fibrillation) symptomatic for syncope. A ventricular lead was implanted in the apical septum, the post–procedural posterior–anterior chest radiograph showed correct placement of the leads and generator. Approximately 4 months after the implant, the patient came to our observation for repeated electric pulsations in his left shoulder. The patient was affected by mild dementia and was asymptomatic except for the presenting symptomatology, in particular he denied a history of syncope. The ECG showed arrhythmia due to atrial fibrillation, ventricular undersensing, and lack of ventricular capture (Figure 1). The chest X–ray showed the complete dislodgement of the ventricular lead tip apparently into the vein secondary to the rotation of the pulse generator on its transverse axis with consecutive coiling of the lead (Fig. 2). These findings were consistent with Reel syndrome The patient was admitted to undergo a lead repositioning attempt in consideration of the recent first implant. During the surgery, however, it was shown that the lead was completely displaced from the venous system, near the pectoral muscle. This extreme dislocation of the lead has been related to the electric pulsations felt by the patient. We proceeded with a new re–implantation of the lead and removal of the previous one. The lead was firmly tied to the pectoral muscle with 2 silk points with slight traction control of optimal fixation. Reel‘s syndrome is a variant of the better known Twiddler syndrome, characterized by the coiling of catheters along the transverse axis of the pacemaker. It is often a complication due to the manipulation of the generator by the patient, unlike Twiddler syndrome it occurs early and the leads remain intact. This syndrome is one of the most serious complications of pacemaker or defibrillator implants, it can be potentially fatal due to lack of therapy in the case of defibrillators, or asystole in pacemaker–dependent patients.

Analysis using physics model to understand magnetoelectric nanorobotic structures for targeted cell manipulation

Magnetoelectric (ME) nanorobotic structures has application in targeted biological cell manipulation and optimized drug delivery. An approximate 70 nm diameter of Cobalt Ferrite- Barium Titanate, ferromagnetic core and piezoelectric shell is studied in context to its ability for nanoelectroporation in biological cell. Physics modeling is performed using COMSOL Multiphysics and quantitative analysis is used to understand the impact of applied magnetic field on the generated mechanical waves and electric pulses. The focus of this paper is to compliment relevant in vitro studies with ME nanorobots and to understand real-time changes in magnetostriction, piezoelectric and nanoelectroporation. The design of the magnetic navigation system with the relevant parameters to generate the required flux density for magnetostriction is discussed extensively. Assuming strong coupling between the core-shell, the 20 nm piezoelectric barium titanate contributes to electric pulsation that alters the membrane permeability leading to increased conductivity. This real time theoretical analysis provides scope for relevant clinical studies for engineering swarm of nm range robotic composites for targeted cell manipulation.

Use of electrochemotherapy in a combined surgical treatment of local recurrence of rectal cancer

Recurrence of rectal cancer (RRC) affects up to one-third of patients. The survival is strictly dependent on the possibility of performing surgery without microscopic tumor residues (R0).Electrochemotherapy (ECT) is based on the effect that electric pulsations have on increasing the permeability of the cell membrane to certain drugs. We propose the association of ECT to the surgical excision of perineal RRC in a 72-year-old male patient. Given the proximity between the recurrence and the urethra, it was decided to use ECT in order to clean any further neoplastic residues 10 mm from the surgical resection margin. Pelvic MRI at 4 and 7 months and clinical follow-up conducted for 9 months did not document disease recurrence. ECT combined with surgery can prove to be a valid choice in selected cases and could be the best treatment the patient is willing to accept.

Low-amperage pulsating direct current has a bactericidal effect on marine fish pathogens in circulating seawater

The bactericidal effect of pulsating direct current (PC) generated at a very low amperage (0.01 A) with a frequency of 5 Hz or 14 kHz against two marine fish pathogens, Edwardsiella tarda and Vibrio parahaemolyticus, in circulating seawater at 15 and 25 °C in comparison with the effect of direct current (DC) of the same amperage was investigated. The bactericidal effect was directly correlated with the generation of active chlorine species (ACS) and the treatment duration. PC treatment at 14 kHz resulted in complete bacterial inactivation when the ACS level reached 0.11–0.12 mg/L after 45–60 min of treatment. PC treatment at 5 Hz required generation of only 0.03–0.07 mg/L ACS to achieve complete bacterial inactivation, although a slightly longer treatment duration (60–90 min) was needed. DC treatment resulted in complete disinfection within a shorter time (30 min) due to greater ACS production. The bactericidal effect and ACS generation were weaker at the higher temperature (25 °C) due to more rapid evaporation of Cl2 gas. The pH of the seawater maintained at ∼8.0. A disinfection study in circulating non-chloride Na2SO4 solution at pH 8.0 showed that the electric pulsation did not have notable bactericidal effect up to 14 kHz at 0.2 A.

Pre-seismic variations of atmospheric radon activity as a possible reason for abnormal atmospheric effects

Possible atmospheric effects associated with pre-seismic variations of atmospheric radon concentration occasionally observed prior to earthquake occurrence are subjected to theoretical study in order to assess their potential effectiveness. Altitude distribution of atmospheric conductivity is examined as a function of radon and aerosol concentrations. Horizontal components of atmospheric electric fields and currents, which can arise near a boundary of seismo-active region, are estimated. We speculated that changes in radon-induced air ionization can have an impact on fair-weather spectra of ULF electric pulsations. Particular emphasis has been placed on hypothesis for correlation between variations of pre-seismic radon activity and upward thermal radiation measured by satellite over the high seismicity regions. This hypothesis is based on assumption that the radon-induced ionization of atmospheric surface layer can trigger water vapor condensation which in turn results in release of the vaporization heat. Our analysis has shown that the upward thermal flux has to be many orders of magnitude lower than that predicted on the basis of this hypothesis.

Collective electronic pulsation around giant nuclei in the Thomas–Fermi model

Based on the Thomas–Fermi solution for compressed electron gas around a giant nucleus, we study electric pulsations of electron number-density, pressure and electric fields, which could be caused by an external perturbations acting on the nucleus or the electrons themselves. We numerically obtain the eigen-frequencies and eigen-functions for stationary pulsation modes that fulfill the boundary-value problem established by electron-number and energy–momentum conservation, equation of state, and Maxwell's equations, as well as physical boundary conditions, and assume the nucleons in β-equilibrium at nuclear density. We particularly study the configuration of ultra-relativistic electrons with a large fraction contained within the nucleus. Such configurations can be realized for a giant nucleus or high external compression on the electrons. The lowest modes turn out to be heavily influenced by the relativistic plasma frequency induced by the positive charge background in the nucleus. Our results can be applied to heavy nuclei in the neutron star crust, as well as to the whole core of a neutron star. We discuss the possibility to apply our results to dynamic nuclei using the spectral method.

Electrotransfection of Mammalian Cells Using Microchannel-Type Electroporation Chip

Transfection of DNA molecules into mammalian cells with electric pulsations, which is so-called electroporation, is a powerful and widely used method that can be directly applied to gene therapy. However, very little is known about the basic mechanisms of DNA transfer and cell response to the electric pulse. We developed a microelectroporation chip with poly(dimethylsiloxane) (PDMS) to investigate the mechanism of electroporation as a first step of DNA transfer and to introduce the benefits of miniaturization into the genetic manipulation. The microelectroporation chip has a microchannel with a height of 20 microm and a length of 2 cm. Owing to the transparency of PDMS, we could in situ observe the uptake process of propidium iodide (PI) into SK-OV-3 cells, which shows promise in visualization of gene delivery in living cells. We also noticed the geometric effect on the degree of electroporation in microchannels with diverse channel width. This experimental result shows that the geometry can be another parameter to be considered for the electroporation when it is performed in microchannels with an exponential decaying pulse generator. Cell culturing is possible within the microelectroporation chip, and we also successfully transfected SK-OV-3 cells with enhanced green fluorescent protein genes, which demonstrates the feasibility of the microelectroporation chip in genetic manipulation.

Transient behaviour in the plasma core of TJ-II stellarator and its relation with rational surfaces*

A transient behaviour is observed in the plasma core of TJ-II stellarator with fast drops in the electron temperature. Changes in the line-averaged density are observed synchronized with temperature drops. This phenomenon appears in plasmas created and heated using 300 kW of electron cyclotron heating with high power density. The transient behaviour resembles both, the electric pulsation discovered in CHS and the `electron root' feature reported by the W7-AS team. The flexibility and low magnetic shear of TJ-II have permitted the identification of the plasma current as the control parameter for the appearance of this phenomenon. The results obtained during the magnetic configuration scans carried out in TJ-II points to the hypothesis that the transient behaviour is connected with the presence of a rational surface close to the plasma centre. Equilibrium calculations performed with the VMEC code reinforce this hypothesis.

In vivo electroporation-mediated transfer of interleukin-12 and interleukin-18 genes induces significant antitumor effects against melanoma in mice.

Direct intratumoral transfection of cytokine genes was performed by means of the in vivo electroporation as a novel therapeutic strategy for cancer. Plasmid vectors carrying the firefly luciferase, interleukin (IL)-12 and IL-18 genes were injected into established subcutaneous B16-derived melanomas followed by electric pulsation. When plasmid vectors with Epstein--Barr virus (EBV) nuclear antigen 1 (EBNA1) gene were employed, the expression levels of the transgenes were significantly higher in comparison with those obtained with conventional plasmid vectors. In consequence of the transfection with IL-12 and IL-18 genes, serum concentrations of the cytokines were significantly elevated, while interferon (IFN)-gamma also increased in the sera of the animals. The IL-12 gene transfection resulted in significant suppression of tumor growth, while the therapeutic effect was further improved by co-transfection with IL-12 and IL-18 genes. Repetitive co-transfection with IL-12 and IL-18 genes resulted in significant prolongation of survival of the animals. Natural killer (NK) and cytotoxic T lymphocyte (CTL) activities were markedly enhanced in the mice transfected with the cytokine genes. The present data suggest that the cytokine gene transfer can be successfully achieved by in vivo electroporation, leading to both specific and nonspecific antitumoral immune responses and significant therapeutic outcome.

Experimental study of the bifurcation nature of the electrostatic potential of a toroidal helical plasma

The bifurcation nature of the electrostatic structure is studied in the toroidal helical plasma of the Compact Helical System (CHS) [K. Matsuoka et al., Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 2, p. 411]. Observation of bifurcation-related phenomena is introduced, such as characteristic patterns of discrete potential profiles, and various patterns of self-sustained oscillations termed electric pulsation. Some patterns of the electrostatic structure are found to be quite important for fusion application owing to their association with transport barrier formation. It is confirmed, as is shown in several tokamak experiments, that the thermal transport barrier is linked with electrostatic structure through the radial electric field shear that can reduce the fluctuation resulting in anomalous transport. This article describes in detail spatio-temporal evolution during self-sustained oscillation, together with correlation between the radial electric field and other plasma parameters. An experimental survey to find dependence of the temporal and spatial patterns on plasma parameters is performed in order to understand systematically the bifurcation property of the toroidal helical plasma. The experimental results are compared with the neoclassical bifurcation property that is believed to explain the observed bifurcation property of the CHS plasmas. The present results show that the electrostatic property plays an essential role in the structural formation of toroidal helical plasmas, and demonstrate that toroidal plasma is an open system with a strong nonlinearity to provide a new attractive problem to be studied.

Experimental Observation of Bifurcation Nature of Radial Electric Field in CHS Heliotron/Torsatron.

Several interesting phenomena, such as the formation of a particular potential profile with a protuberance around the core and oscillatory stationary states termed electric pulsation, have been discovered using a heavy ion beam probe in the electron cyclotron heated plasmas of the CHS. This paper presents experimental observations which indicate that bifurcation of the radial electric field is responsible for such phenomena; existence of an ECH power threshold to obtain the profile with a protuberance, and its striking sensitivity to density. In particular, flip-flop behavior of the potential near the power threshold clearly demonstrates bifurcation characteristics. Bifurcation of radial electric field in neoclassical theory is presented, and its qualitative expectation is discussed in the bifurcation phenomena. The neoclassical transition time scale between two bifurcative states is compared with the experimental observations during the electric pulsation. It is confirmed that the neoclassical transition time is not contradictory with the experimental one.

Electric pulsation and profile quantization in CHS heliotron/torsatron

Radial electric field is a key physical quantity in determining the structure of toroidal helical plasmas, owing to the nonlinear dependence of transport on the radial electric field. It has been observed that the potential profiles show various interesting patterns in space and time in the compact helical system (CHS) plasmas. In particular, the phenomenon of electric pulsation, clearly demonstrates the nature of bifurcation of radial electric field in toroidal helical plasmas.

Discovery of Electric Pulsation in a Toroidal Helical Plasma

Discovery of Electric Pulsation in a Toroidal Helical Plasma

Cytoskeletal reorganization during electric-field-induced fusion of Chinese hamster ovary cells grown in monolayers

Mammalian cells were shown to fuse after direct electric pulsation of the plated cells in culture. The extent of fusion was controlled by the duration of the post-pulse incubation. Formation of polynucleated cells was slow, even at 37°C, Pre-pulse incubation with colchicine increased the fusion yield slightly. Cytoskeletal organization during the post-pulse incubation was observed using immunofluorescence techniques. Microfilaments were unaffected, but microtubules disapepared during the first minutes following the pulse, and then reformed on subsequent incubation.

Degeneration of an isotropic random field of electric charge pulsations in electrodynamics

The conditions under which an isotropic field of electric pulsations can exist in an electrically charged medium are indicated, with allowance in Ohm's law for the convection and diffusion of charged particles and their drift in the electric field. Mean parameter distributions are found for isotropic random fields and equations are obtained for correlation moments containing electric pulsations. The equations are analyzed with respect to the two-point correlations between the pulsations in the electric charge densities (the limit of single-point correlations is reached, invariant relations are obtained, and particular solutions are constructed). The degeneration laws of the isotropic fields of the electric parameters as a result of diffusion and drift. processes are found. Field degeneration due only to drift particle motion is studied under arbitrary initial conditions. Such field degeneration if there is no diffusion mechanism is a fundamental feature of turbulent electro-hydrodynamic motions.

Volume and ionic composition changes in erythrocytes after electric breakdown: Simulation and experiment

A complex mathematical model was set up to describe the changes in human red cells that are initiated by electric breakdown of the membrane (ionic composition, influx of impermeable substances, volume, transmembrane potential). Experimentally measurable characteristics, such as volume, hemolysis and conductivity of the suspension, were calculated as a function of the initial conditions and permeability changes induced by the application of an electric field. As a result of certain conditions of electric pulsation, ionic and sucrose permeability could be determined from volume changes of the cells, which were measured by a light-scattering method. The decrease in permeability due to resealing of the pores was investigated experimentally. It showed a complex exponential behaviour, which could be described empirically by three parameters. The model provides a useful theoretical basis for determining favourable conditions for electrofusion and for the incorporation of substances into cells as well as for estimating the extent of cell damage due to electropulsation.

Joint Interpretation of magnetotelluric and geomagnetic data and local telluric distortions.

Magnetotelluric and geomagnetic depth-sounding surveys were made in the Harz Mountains, Germany, to investigate the conductivity structure across its northern edge as well as the extension of crystalline intrusions inside the mountains. Magnetic and electric pulsations were recorded along a north-south-profile of 80km length. Because the statioins were recording simultaneously, transfer functions for anomalous horizontal and vertical magnetic variations could be obtained with the north end station defined as normal. Their amplitude and phase indicate a large-scale discontinuity in conductivity.This model explains well the smooth behaviour of the magnetic transfer functions but not the telluric impedances and their distinct changes from site to site. For this reason a special study of the effects of local anomalous conductivity zones on the telluric field was carried out. The impedances found there are influenced by strong direct-current distortions. Furthermore, a vertical electric field was detected inside the uppermost layer. Because it is also associated with a local anomaly, it can be used to determine the orientation and magnitude of that anomaly.

On the Electric Pulsation accompanying Automatic Movements in Desmodium gyrans, DC.

On the Electric Pulsation accompanying Automatic Movements in Desmodium gyrans, DC.