Application Of Electric Pulses Research Articles

Abstract P5-22-23: Electrochemotherapy : A new local therapy for cutaneous metastases of breast cancer

Abstract Background : Electrochemotherapy (ECT) is a new local therapy combining the administration of an intravenous chemotherapy (bleomycin) followed by the direct application of electric pulses by an electrode to the treated areas. Electric pulses transiently permeabilize the membrane of the tumor cell ( electroporation), improving intracellular diffusion of a poorly permeant chemotherapeutic agent, ithereby ncreasing its cytotoxicity and decreasing systemic toxicity. ECT can be offered to patients with cutaneous or subutaneous metastases of breast cancer who are no longer suitable for extensive surgery or radiotherapy ( e.g. due to past irradiation of the breast or chest wall). ECT 's applications are palliative. It is -, delivered with the aim of local control of the tumor, relief of symptoms associated with cutaneous recurrence -(ulceration, bleeding, pain),i and mproving patients'quality of life. The aim of this study is to demonstrate that ECT has a high efficacity and a low toxicity profile making it an interesting alternative to conventional therapies. Material and methods : our study is a retrospective study (approved by our local ethics committee) which included 8 patients between June 2013 and June 2016. The patients had histologically proven cutaneous and or subcutaneous metastases of their breast cancer, without any sign of lymphangitis. All the tumors expressed ER and /or PgR and 2 of them were HER2 positive tumors. The patients received a single or multiple courses of ECT ; the outcomes were clinical response, toxicity, local and distant recurrence. The two patients whose tumors expressed HER2, also had synchronous controlateral axillary nodal metastases. They underwent axillary dissection performed during ECT course. Among the six other patients, no other metastases than cutaneous lesions were observed. Results : The 8 included patients had already received chest wall irradiation for the treatment of their primary breast cancer. A total of 37 nodules were treated (mean : 4.5 per patient), whose mean size was 17mm (10-34mm). Six patients(75%) had a complete response after a single course of ECT. Two patients exhibited a partial response and underwent a second course of ECT at 6 months. The two patients with Her2 positive tumors received taxane-based chemotherapy and anti HER2 agents. All the patients were also given endocrine therapy. After a median follow up of 26 months (11-47 months), no patient had a local cutaneous recurrence. Overall survival rate was 75% : 2 patients died following progression of systemic disease (pulmonary and hepatic metastases). No complications due to toxicity were observed. Discussion and conclusion :In selected patients with ( cutaneous and subcutaneous metastases of breast cancer with no sign of lymphangitis), ECT offers a very good rate of clinical response and a durable control of metastases. This innovative technique has the advantage of being minimally –invasive and well –tolerated. Citation Format: Berliere M, Raguzzi E, Bernard M, Gerday A, Coyette M, Piette P, Duhoux F, Lengele B. Electrochemotherapy : A new local therapy for cutaneous metastases of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-23.

Successful Treatment of a Keratoacanthoma with Electrochemotherapy: A Case Report.

IntroductionFew studies have evaluated the efficacy of intralesional bleomycin injection combined with electroporation for the treatment of cutaneous tumors. However, the phenomenon that electroporation can enhance the cytotoxicity of bleomycin in vivo by 300–700 fold has been intensely investigated.Case PresentationKeratoacanthoma in an 86-year-old patient was treated with intralesional bleomycin combined with electroporation. Treatment consisted of local application of shorty and intense electric pulses followed by local injection of bleomycin. Electroporation was always well tolerated by the patient, with no significant complaints, and the tumor had completely regressed by day 71 of the follow-up.ConclusionThe results suggest that intralesional bleomycin injection combined with electroporation could represent a valid alternative therapeutic approach for the treatment of keratoacanthomas.

Electroporation with Cisplatin against Metastatic Pancreatic Cancer: In Vitro Study on Human Primary Cell Culture.

Despite the rapid progression of cancer pharmacotherapy, the high drug resistance of pancreatic ductal adenocarcinoma (PDA) makes it one of the most lethal malignancies. Therefore, there are high expectations associated with experimental therapies, such as electrochemotherapy (ECT). This technique involves the application of short electric pulses to induce transitional permeabilization of the cellular membrane, thus enhancing drug molecules influx. The aim of the study was to investigate the influence of electroporation with cisplatin (CisEP) on the primary culture of human PDA cells from lung metastases—their survival and stress response. Considering the growing importance of various research models, two established human PDA cell lines, EPP85-181P (sensitive to daunorubicin) and EPP85-181RDB (resistant to daunorubicin), were utilized as a reference control. Cisplatin revealed higher cytotoxicity towards established cell lines. Following CisEP application, we observed a significant decrease of cells viability in the primary culture model. After CisEP therapy, an increased immunoreactivity with SOD-2 and Casp-3 antibodies was noticed. In conclusion, we discovered that electroporation can enhance the cytotoxic effect of cisplatin in pancreatic cancer cells in vitro. This effect was evident for cells from the primary culture. The obtained results confirm the importance of primary cells models in studies on the efficacy of experimental cancer therapies.

Electrochemotherapy of unresectable cutaneous tumours with reduced dosages of intravenous bleomycin: analysis of 57 patients from the International Network for Sharing Practices of Electrochemotherapy registry.

Electrochemotherapy (ECT) is currently used to treat unresectable superficial tumours of different histotypes through the combination of cytotoxic chemotherapy and local application of electric pulses. In 2006, a collaborative project defined the ESOPE (European Standard Operating Procedures of Electrochemotherapy) guidelines to standardize the procedure. The International Network for Sharing Practices of Electrochemotherapy (InspECT) aims to refine the ESOPE and improve clinical practice. Limiting patient exposure to systemic chemotherapy would be advisable to ameliorate ECT safety profile. The aim of this study was to evaluate the efficacy and toxicity of ECT with reduced chemotherapy dosages. In a retrospective analysis of a prospectively maintained database (InspECT registry), we evaluated the outcome of patients who received ECT with reduced dosages of bleomycin (7500, 10 000 or 13 500 IU/m2 , instead of the standard dose of 15 000 IU/m2 ). Tumour response in melanoma patients was compared with melanoma patients of the InspECT registry who received the standard dose of bleomycin. We identified 57 patients with 147 tumours (melanoma, 38.6%; squamous cell carcinoma, 22.8%; basal cell carcinoma, 17.5%; breast cancer 7%; Kaposi sarcoma 7%; other histotypes, 7.1%). Per-tumour complete response (CR) rate at 60 days was 70.1% (partial, 16.3%); per-patient CR was 57.9% (partial, 21.1%). Local pain was the most frequently reported side-effect (n = 22 patients [39%]), mostly mild; two patients experienced flu-like symptoms, one patient nausea. We observed the same CR rate (55%) in patients with melanoma treated by reduced or conventional bleomycin dosages (P = 1.00). Electrochemotherapy performed with reduced bleomycin dosages could be as effective as with currently recommended dose. Patients with impaired renal function or candidate to multiple ECT cycles could benefit from a reduced dose protocol. Our findings need prospective confirmation before being adopted in clinical practice.

Membrane cleaning using electric pulse in dead end ultrafiltration of proteinaceous solution

Dead end ultrafiltration of Bovine Serum Albumine (BSA) using a polymeric membrane has been studied. Membrane fouling for such fine biological product due to the formation of filter cake and adsorption of the proteinaceous solution is the major bottleneck for such separation process. The application of electric pulses has shown an effective means in cleaning the membrane and reducing the fouling rate for dead-end ultrafiltration of BSA. The flux is significantly increased by both electrophoretic motion of solutes away from the membrane surface and electro-osmosis occurring in the filter cake. An automated experimental rig equipped with data acquisition system has been developed to test the effectiveness and performance of such membrane cleaning. The improvement of flux becomes more pronounced with increasing electric field strength. The effects of other processing variables such as pulse interval, pulse duration, ionic strength of the electrolyte, pH of the solution and solution concentration were studied on this membrane cleaning technique. Data are analysed for its average flux, average cake concentration, average percentage of cake and water recovery for every cleaning condition. It is found out that the chemical and physical properties of the solution (pH and ionic strength of the electrolyte) have a great effect on this membrane cleaning method. Protein solution at pH 8 and 0.0 lM ionic strength of the electrolyte gave the best membrane cleaning performance. Shorter pulse interval and with relatively 10 seconds pulse duration are the optimum conditions on application of pulse to remove the filter cake from the membrane.

Investigation of the chemical mechanisms involved in the electropulsation of membranes at the molecular level

The chemical consequences of electropulsation on giant unilamellar vesicles (GUVs), in particular the possible oxidation of unsaturated phospholipids, have been investigated by mass spectrometry, flow cytometry and absorbance methods. Pulse application induced oxidation of the GUV phospholipids and the oxidation level depended on the duration of the pulse. Light and O2 increased the level of pulse-induced lipid peroxidation whereas the presence of antioxidants either in the membrane or in the solution completely suppressed peroxidation. Importantly, pulse application did not create additional reactive oxygen species (ROS) in GUV-free solution. Lipid peroxidation seems to result from a facilitation of the lipid peroxidation by the ROS already present in the solution before pulsing, not from a direct pulse-induced peroxidation. The pulse would facilitate the entrance of ROS in the core of the membrane, allowing the contact between ROS and lipid chains and provoking the oxidation. Our findings demonstrate that the application of electric pulses on cells could induce the oxidation of the membrane phospholipids since cell membranes contain unsaturated lipids. The chemical consequences of electropulsation will therefore have to be taken into account in future biomedical applications of electropulsation since oxidized phospholipids play a key role in many signaling pathways and diseases.

Finite Element Analysis of Tissue Conductivity during High-frequency and Low-voltage Irreversible Electroporation

Introduction: Irreversible electroporation (IRE) is a process in which the membrane of the cancer cells are irreversibly damaged with the use of high-intensity electric pulses, which in turn leads to cell death. The IRE is a non-thermal way to ablate the cancer cells. This process relies on the distribution of the electric field, which affects the pulse amplitude, width, and electrical conductivity of the tissues. The present study aimed to investigate the relationship of the pulse width and intensity with the conductivity changes during the IRE using simulation. Materials and Methods: For the purpose of the study, the COMSOL 5 software was utilized to predict the conductivity changes during the IRE. We used 4,000 bipolar and monopolar pulses with the frequency of 5 kHz and 1 Hz, width of 100 µs, and electric fields of low and high intensity. Subsequently, we built three-dimensional numerical models for the liver tissue. Results: The results of our study revealed that the conductivity of tissue increased during the application of electrical pulses. Additionally, the conductivity changes increased with the elevation of the electric field intensity. Conclusion: As the finding of this study indicated, the IRE with high-frequency and low electric field intensity could change the tissue conductivity. Therefore, the IRE was recommended to be applied with high frequency and low voltage.

(Invited) Quantification and Manipulation of the Microelectrode-Tissue Interface for Neural Prostheses

The quality of the information transfer available utilizing a chronically implanted neural interface likely depends upon the quality of the electrode-tissue interface. High density, high-fidelity neural interfaces require small electrode site areas; unfortunately, these electrodes typically have high initial impedances, as well as exhibit impedance drift post-implant. Here we will discuss our efforts to elucidate and control this electrochemical effect. One mechanism to address initial high-impedance microelectrode interfaces is by applying surface coatings to the metal sites. In this report we quantify the in vitro stability and in vivoperformance of poly(3,4-ethylenedioxythiophene) (PEDOT) and compare with iridium oxide (IrOx) for microstimulation applications. Commercially available neural implants (NeuroNexus) with iridium metal sites were either activated to form IrOx or coated with PEDOT. Biphasic current stimulation was then administered in phosphate buffered saline continuously for two hours at the maximum safe level of charge density determined by Shannon (1992). Prior to stimulation, the PEDOT coated sites displayed lower 1 kHz impedances, higher charge storage capacities and lower amplitude voltage excursions than IrOx sites. After stimulation, PEDOT coated sites displayed no significant change in their impedance, cyclic voltammetry (CV) and voltage excursion measurements, while 1 kHz impedance increased and CVs displayed unstable, pulse-induced activation for the IrOx sites. Typically, regardless of surface modification, chronically implanted neural microelectrodes exhibit increases in impedance magnitude, as well as decreases in the signal-to-noise ratio of electrophysiology. Both of these effects are detrimental for microelectrode-based neuroprosthetic systems. It has been suggested that the reactive tissue response to device implantation may be the main cause of these impedance changes. Previously we have used lumped-circuit element models fit to impedance spectroscopy data to estimate several of these device-tissue interface parameters. Further, we have utilized brief voltage pulses to affect these parameters for a period on the order of hours. One method shown to temporarily mitigate this response and thus improve the interface quality is delivery of a short-duration DC bias voltage to the electrode site (Johnson et al. 2005; Otto et al. 2006). While this method has successfully recovered electrical signals from the interface, other research demonstrates that application of a charge-imbalanced waveform may be harmful to the electrode or electrode-tissue interface. Here, we report the effect of applying charge-balanced sinusoidal AC waveforms on the electrode-tissue interface. We utilized impedance spectroscopy as well as cyclic voltammetry in order to quantify the interface. We use in vitro experiments using 0.9% phosphate buffered saline, varying waveform amplitude, duration, and frequency. In vitro results suggest that, within-limits, charge-balanced waveforms are safer for application of electrical pulses. Subsequent in vivo experiments were conducted using chronically implanted male Long-Evans rats, and cyclic voltammetry, impedance spectroscopy, and electrophysiology measurements were performed.

Calcium electroporation for treatment of cutaneous metastases; a randomized double-blinded phase II study, comparing the effect of calcium electroporation with electrochemotherapy

Background: Calcium electroporation is a novel anticancer treatment, which utilizes high voltage pulses to permeabilize cell membranes and expose the cell to supraphysiological doses of calcium. Preclinical studies on calcium electroporation have shown strikingly high tumor response with cell necrosis. Calcium electroporation builds on the treatment electrochemotherapy, where chemotherapeutic drugs, mostly bleomycin, are internalized by electroporation. This double-blinded randomized study compared calcium electroporation to electrochemotherapy in terms of objective response measured 6 months after treatment.Methods: Seven patients with a total of 47 cutaneous metastases from breast cancer and malignant melanoma were included in the protocol. A total of 37 metastases were randomized and evaluated for response, another 10 metastases were used for biopsy. This was a non-inferiority trial and metastases were randomized individually in each patient to either intratumoral calcium or bleomycin followed by application of electric pulses to tumor site. All metastases were treated once, and after 6-months of follow-up, the randomization code was revealed.Results: Objective response of calcium electroporation was 72% (13/18) with complete response in 66% (12/18). For electrochemotherapy, objective response was 84% (16/19) with complete response in 68% (13/19). There was no statistically significant difference between the two treatments (p = 0.5). After 1 year, only three out of 25 metastases had relapsed. Ulceration, itching and exudation were reported slightly more frequently in metastases treated with bleomycin, and hyperpigmentation was only seen in metastases treated with bleomycin.Conclusion: This study shows that calcium electroporation is feasible and effective in patients with cutaneous metastases.

Highly sensitive protein detection by biospecific AFM‐based fishing with pulsed electrical stimulation

We report here the highly sensitive detection of protein in solution at concentrations from 10–15 to 10–18 m using the combination of atomic force microscopy (AFM) and mass spectrometry. Biospecific detection of biotinylated bovine serum albumin was carried out by fishing out the protein onto the surface of AFM chips with immobilized avidin, which determined the specificity of the analysis. Electrical stimulation was applied to enhance the fishing efficiency. A high sensitivity of detection was achieved by application of nanosecond electric pulses to highly oriented pyrolytic graphite placed under the AFM chip. A peristaltic pump‐based flow system, which is widely used in routine bioanalytical assays, was employed throughout the analysis. These results hold promise for the development of highly sensitive protein detection methods using nanosensor devices.

Purification of Drinking Water by Application of High Voltage Electric Pulses Generated from Boost Converter and Voltage Multipliers

Purification of Drinking Water by Application of High Voltage Electric Pulses Generated from Boost Converter and Voltage Multipliers

A comprehensive theoretical study of thermal relations in plant tissue following electroporation

Electroporation is the application of electric pulses of sufficient amplitude to target tissue, which entails not only permeabilization of cell membranes, but also heat generation and dissipation. Noticeable rises in temperature have been observed in a number of electroporation applications. These temperature rises are a potential source of alteration of thermodynamic properties of tissue wherein mass transport is occurring. Transport parameters are temperature-dependent, as they relate to thermodynamic processes.This paper presents a theoretical study of thermal relations in tissue immediately following electroporation. An analysis of thermal transfer characteristics of tissue based on available data from literature is performed, and a model of heat transfer in tissue is presented. The tissue is modelled as a porous medium, and the chosen model for analysis, which we call the dual-porosity model, is a two-temperature model developed for heterogeneous porous materials. The dual-porosity model in its given form is a particular example of a LaLoThEq (Lack of Local Thermal Eqilibrium) model. This model is used to evaluate the potential for any significant alteration of cell membrane’s thermal conductivity due to electroporation, and examines whether electroporation thus directly influences heat redistribution in tissue.The main result is an in-depth theoretical analysis on the potential influence of electroporation on heat transfer characteristics of tissue via any direct influence of the treatment to the cell membrane. Findings of the study indicate that, on the contrary to the effects of electroporation on mass transport in tissue, the treatment would appear to exert a negligible influence on heat redistribution, at least due to its direct impact on the cell membrane. Other impacts of electroporation that could potentially result in a heterogeneous heat (re)distribution in tissue are briefly discussed, albeit not the subject of this study.

Electroplastic behaviour in an aluminium alloy and dislocation density based modelling

Electroplasticity refers to the application of controlled electric pulses during plastic deformation of materials. The electroplasticity phenomenon in metallic materials has led to the development of electrically assisted forming (EAF) process with improved formability. The lack of a suitable constitutive model to describe this electroplastic behaviour is a serious limitation in modelling and optimizing the EAF process. In the present work, a dislocation – density based constitutive model is developed for electroplastic deformation and is capable of predicting the effect of continuous and pulsed electric current during plastic deformation. Single- pulse electroplastic deformation experiments conducted on Al 5052 reveal similar mechanical behaviour as that predicted by the proposed model. The proposed model is also validated against published results for multiple electric pulses using Al 5052. The predicted results correlate well with the experimental data. Based on the predicted results, it is demonstrated that the long range softening observed in certain experiments results from the frequent application of electric pulses and is not due to any other internal softening mechanism.

Avoiding the side effects of electric current pulse application to electroporated cells in disposable small volume cuvettes assures good cell survival

BackgroundThe harmful side effects of electroporation to cells due to local changes in pH, the appearance of toxic electrode products, temperature increase, and the heterogeneity of the electric field acting on cells in the cuvettes used for electroporation were observed and discussed in several laboratories. If cells are subjected to weak electric fields for prolonged periods, for example in experiments on cell electrophoresis or galvanotaxis the same effects are seen. In these experiments investigators managed to reduce or eliminate the harmful side effects of electric current application.MethodsFor the experiments, disposable 20 μl cuvettes with two walls made of dialysis membranes were constructed and placed in a locally focused electric field at a considerable distance from the electrodes. Cuvettes were mounted into an apparatus for horizontal electrophoresis and the cells were subjected to direct current electric field (dcEF) pulses from a commercial pulse generator of exponentially declining pulses and from a custom-made generator of double and single rectangular pulses.ResultsMore than 80% of the electroporated cells survived the dcEF pulses in both systems. Side effects related to electrodes were eliminated in both the flow through the dcEF and in the disposable cuvettes placed in the focused dcEFs. With a disposable cuvette system, we also confirmed the sensitization of cells to a dcEF using procaine by observing the loading of AT2 cells with calceine and using a square pulse generator, applying 50 ms single rectangular pulses.ConclusionsWe suggest that the same methods of avoiding the side effects of electric current pulse application as in cell electrophoresis and galvanotaxis should also be used for electroporation. This conclusion was confirmed in our electroporation experiments performed in conditions assuring survival of over 80% of the electroporated cells. If the amplitude, duration, and shape of the dcEF pulse are known, then electroporation does not depend on the type of pulse generator. This knowledge of the characteristics of the pulse assures reproducibility of electroporation experiments using different equipment.

How Imaging Membrane and Cell Processes Involved in Electropermeabilization Can Improve Its Development in Cell Biology and in Clinics.

Cell membranes can be transiently permeabilized under the application of electric pulses. This process, called electropermeabilization or electroporation, allows hydrophilic molecules, such as anticancer drugs and DNA, to enter into cells and tissues. The method is nowadays used in clinics to treat cancers. Vaccination and gene therapy are other fields of application of DNA electrotransfer. A description of the mechanisms can be assayed by using different complementary systems with increasing complexities (models of membranes, cells cultivated in 2D and 3D culture named spheroids, and tissues in living mice) and different microscopy tools to visualize the processes from single molecules to entire animals. Single-cell imaging experiments revealed that the uptake of molecules (nucleic acids, antitumor drugs) takes place in well-defined membrane regions and depends on their chemical and physical properties (size, charge). If small molecules freely cross the electropermeabilized membrane and have a free access to the cytoplasm, larger molecules, such as plasmid DNA, face physical barriers (plasma membrane, cytoplasm crowding, nuclear envelope) which reduce transfection efficiency and engender a complex mechanism of transfer. Gene electrotransfer indeed involves different steps that include the initial interaction with the membrane, its crossing, transport within the cytoplasm, and finally gene expression. In vivo, additional very important effects of electric pulses are present such as blood flow modifications. The full knowledge on the way molecules are transported across the electropermeabilized membranes and within tissues is mandatory to improve the efficacy and the safety of the electropermeabilization process both in cell biology and in clinics.

Impact of Pulsed Direct Current on Embryos, Larvae, and Young Juveniles of Atlantic Cod and its Implications for Electrotrawling of Brown Shrimp

AbstractThe application of electrical pulses in fishing gear is considered a promising option to increase the sustainability of demersal trawl fisheries. In the electrotrawl fishery for brown shrimp Crangon crangon, an electrical field selectively induces a startle response in the shrimp. Other benthic organisms remain mainly on the seafloor and escape underneath a hovering trawl. Previous experiments have indicated that this pulse has no short‐term major harmful effects on adult fish and invertebrates. However, the impact on young marine life stages is still unknown. Because brown shrimp are caught in shallow coastal zones and estuaries, which serve as important nurseries or spawning areas for a wide range of marine species, electrotrawling on these grounds could harm embryos, larvae, and juveniles. We carried out experiments with different developmental stages of Atlantic Cod Gadus morhua, which are considered vulnerable to electrical pulses. Three embryonic stages, four larval stages, and one juvenile stage of Atlantic Cod were exposed to a homogeneous electrical field of 150 Vpeak/m for 5 s, mimicking a worst‐case scenario. We detected no significant differences in embryo mortality rate between control and exposed groups. However, for the embryonic stage exposed at 18 d postfertilization, the initial hatching rate was lower. Larvae that were exposed at 2 and 26 d posthatch exhibited higher mortality rates than the corresponding nonexposed control groups. In the other larval and juvenile stages, no short‐term impact of exposure on survival was observed. Morphometric analysis of larvae and juveniles revealed no differences in measurements or deformations of the yolk, notochord, eye, or head. Although exposure to a worst‐case electrical field did not impact survival or development for six of the eight young life stages of Atlantic Cod, the observed delayed hatching rate and decreased survival for larvae might indicate an impact of electric pulses and warrant further research.

Recent advances in pulsed electric field and non-thermal plasma treatments for food and biorefinery applications

In the last decays pulsed electric field techniques gained increasing importance in biotechnology and food production. Application of electric pulses to cells leads to increased permeability and conductivity of cell membranes and formation of pores in cell membrane - phenomenon called electroporation. Electroporation could be a very suitable technique for improvement of extraction or dying in both food processing and biorefinery. Non-thermal plasma treatment generates reactive species in the samples causing damage of the cell membrane and could be used for wastewater treatment, microbial inactivation and as a treatment prior to open fermentations on complex substrates. In this study, recent advances in pulsed electric field treatment of food, algal biomass and hospital wastewater as well as role of non-thermal plasma treatment in bio-decontamination of complex substrates will be addressed. Also, some environmental and economic aspects of these novel techniques in comparison to conventional treatments will be discussed.

Electric-field-stimulated protein mechanics.

The internal mechanics of proteins-the coordinated motions of amino acids and the pattern of forces constraining these motions-connects protein structure to function. Here we describe a new method combining the application of strong electric field pulses to protein crystals with time-resolved X-ray crystallography to observe conformational changes in spatial and temporal detail. Using a human PDZ domain (LNX2PDZ2) as a model system, we show that protein crystals tolerate electric field pulses strong enough to drive concerted motions on the sub-microsecond timescale. The induced motions are subtle, involve diverse physical mechanisms, and occur throughout the protein structure. The global pattern of electric-field-induced motions is consistent with both local and allosteric conformational changes naturally induced by ligand binding, including at conserved functional sites in the PDZ domain family. This work lays the foundation for comprehensive experimental study of the mechanical basis of protein function.

Effective treatment of intractable cutaneous metastases of breast cancer with electrochemotherapy: Ten-year audit of single centre experience.

Electrochemotherapy (ECT) is the application of electric pulses to tumour tissue to render the cell membranes permeable to usually impermeant hydrophilic anti-cancer drugs, thereby enhancing cytotoxic effects. We sought to ascertain whether ECT can be an effective palliative treatment for cutaneous metastases of breast cancer. This work reports data from the European Standard Operating Procedures for Electrochemotherapy trial (EudraCT Number: 2004-002183-18). In combination with systemic and/or intratumoural bleomycin, optimised electric pulses were delivered to locally recurrent or metastatic cutaneous breast cancer lesions. Follow-up continued until December 2014. Between February 2004 and December 2014, twenty-four patients were treated. All patients had received prior multimodal therapy. In total, the patient cohort had, or developed, 242 lesions. Two hundred and 36 lesions were treated, with 34 lost to follow-up. An objective response was seen in 161 of 202 lesions (79.7%), with a complete response observed in 130 (64.3%). Thirty-nine lesions (19.3%) did not respond, while 2 (1%) progressed following ECT. 17 (73.9%) patients received two or fewer treatments. A minimum of a partial response was seen in at least 50% of treated lesions in 18 of the 24 (75%) patients. Smaller lesions were more likely to have an objective response (Chi-square test for trend, p<0.001). Electrochemotherapy is an effective treatment for cutaneous breast cancer lesions that have proven refractory to standard therapies. As smaller lesions were found to be more responsive, we suggest that ECT should be considered as an early treatment modality, within multimodal treatment strategies.

Microstructural Evolution of AZ31 under the Application of High Density Electric Current Pulses

The microstructural evolution in annealed Mg-3Al-1Zn (AZ31) magnesium alloy during high density electric current pulses (ECP) treatment is investigated by using a same current density with different processing numbers. It is found when the processing number of the ECP treatment is not greater than four times, the grains are refined and more homogenized, and the texture intensity obtained from the (0002) pole figure appears an obvious enhancement from 11.22 to 22.88. However, increasing the repeated ECP processing number will cause the coarsening of grain size and the decreasing of the texture intensity. The mechanism of the microstructural evolution during ECP treatment is discussed from the point of view of grain boundary motion.