Abstract：
:Although high-intensity electric fields (HEF) application is currently the only effective therapy available to terminate ventricular fibrillation, it may cause injury to cardiac cells. In this study we determined the relation between HEF pulse length and cardiomyocyte lethal injury. We obtained lethality curves by survival analysis, which were used to determine the value of HEF necessary to kill 50% of cells (E50) and plotted a strength-duration (SxD) curve for lethality with 10 different durations: 0.1, 0.2, 0.5, 1, 3, 5, 10, 20, 35 and 70 ms. For the same durations we also obtained an SxD curve for excitation and established an indicator for stimulatory safeness (stimulation safety factor - SSF) as the ratio between the SxD curve for lethality and one for excitation. We found that the lower the pulse duration, the higher the HEF intensity required to cell death. Contrary to expectations, the highest SSF value does not correspond to the lowest pulse duration but to the one of 0.5 ms. As defibrillation threshold has been described as duration-dependent, our results imply that the use of shorter stimulus duration - instead of the one typically used in the clinic (10 ms) - might increase defibrillation safeness.
journal_name
Gen Physiol Biophysjournal_title
General physiology and biophysicsauthors
Prado LN,Goulart JT,Zoccoler M,Oliveira PXdoi
10.4149/gpb_2015047subject
Has Abstractpub_date
2016-04-01 00:00:00pages
121-30issue
2eissn
0231-5882issn
1338-4325journal_volume
35pub_type
杂志文章abstract：:Fusion of neuraminidase or trypsin pretreated human erythrocytes and untreated cells was performed. The obtained doublets had a permanent dipole moment which disappeared as a function of time. Since the dipole moment disappearance is due to protein interdiffusion the lateral diffusion constant may be determined. This ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1984-06-01 00:00:00
abstract：:The complex formation between metmyoglobin and heparin was investigated by absorbance and fluorescence spectroscopy as well as differential scanning microcalorimetry. In acidic pH region, three distinct complexes detected by absorbance measurements are formed depending on pH and time of equilibration. The kinetics of ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1998-06-01 00:00:00
abstract：:Two types of electrocardiographic data series were investigated using appropriate tests based on a selection of semi-quantitative analysis algorithms. Distribution histograms, power spectra, auto-correlation functions, state-space portraits, Lyapunov exponents and wavelet transformations were applied to electrocardiog...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2006-06-01 00:00:00
abstract：:The passive mechanical properties of whole muscle in active and nonactive states are compared. The experimental results are presented as stress-strain curves, which are analyzed in the framework of the current theoretical background [viz. the freely-jointed chain model (FJCM) and the worm-like chain model (WLCM)] in a...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1999-06-01 00:00:00
abstract：:Icaritin, a prenylflavonoid derivative from Epimedium Genus, has been reported to exhibit tumor inhibitory effects on many types of tumor cells. Numerous studies have demonstrated that microRNAs (miRs) involve in the biological process of carcinogenesis by controlling expression of their target mRNAs to facilitate tum...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2019041
更新日期：2019-11-01 00:00:00
abstract：:The aim of the present study was to investigate the ability of the chloroacetanilide herbicide acetochlor to interact with the endocrine system. The modulation of the binding of [3H]estradiol-17beta to protamine sulphate-precipitated uterine nuclear and cytoplasmic estrogen receptors was analysed for this purpose. Two...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2000-03-01 00:00:00
abstract：:A number of studies have reported that male reproductive organs are susceptible to electromagnetic fields (EMFs). The aim of this study was to explore the effects of microwave radiation exposures on 6-8 weeks old male Swiss albino mice. Mice were divided into two groups: group I - sham-exposed (Control), and group II ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017059
更新日期：2018-07-01 00:00:00
abstract：:Ischemic and reperfusion injury is a serious condition related to numerous biochemical and electrical abnormalities of the myocardium. It has been repeatedly studied in various animal models. In this study, the production of hydroxyl radicals and electrophysiological parameters were compared in three species. Rat, gui...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013016
更新日期：2013-06-01 00:00:00
abstract：:Although numerous studies have shown the existence of various types of ion conductance in antral part of gastric fundus mucosa epithelia of amphibian, practically no data are available on ion conductance in higher animal species. Present experiments were undertaken to check the possible existence of ion conductance in...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1995-12-01 00:00:00
abstract：:The action of the antiviral drug rimantadine on the structure of bilayer lipid membranes (BLM) and RBC membranes was investigated. Structural changes in BLM were recorded by ionophore conductivity changes and by changes in the third harmonic of capacity current signal due to lateral compression of BLM in an electric f...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1989-02-01 00:00:00
abstract：:The purpose of this study was to assess the possible protective effects of Artemisia campestris against fenthion-induced nephrotoxicity in adult rats and their progeny. Fenthion was administered orally at a dose of 551 ppm, which represented ¼ of LD50, for 21 consecutive days to pregnant and lactating rats. Oxidative ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013047
更新日期：2013-12-01 00:00:00
abstract：:The effects of ryanodine on negative force staircase and potentiated rested-state contraction (RC) in rat myocardium were compared to the action of Ca release stimulator (caffeine) and inhibitors (local anesthetics). Only low ryanodine concentrations (0.1-0.5 mumol/l) were found to reverse anomalous mechanical pattern...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1988-02-01 00:00:00
abstract：:The aim of this paper was to study the protein remodelling of the left ventricle following repeated administration of either daunorubicin (DNR) or DNR in combination with the cardioprotective agent dexrazoxane (DXZ). The experiment was carried out on three groups of Chinchilla male rabbits: 1. DNR (3 mg/kg i.v.), 2. D...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2003-09-01 00:00:00
abstract：:The hyperpolarisation of the membrane potential in Characeae above that of the diffusion potential is explained by the operation of the electrogenic proton pump. We studied the interaction of calcium with the functioning of the pump. The membrane potential was measured using the standard microelectrode technique. An i...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:Overconsumption of fructose increases the risk of nonalcoholic fatty liver disease (NAFLD), obesity and metabolic syndrome. NAFLD is currently one of the most common etiologies of chronic liver disease worldwide. The aim of the present study is to evaluate the hepatoprotective potential of zingerone against fructose-e...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2015041
更新日期：2016-04-01 00:00:00
abstract：:In P-gp-positive cell variants obtained from L1210 cells either by selection with vincristine (L1210/R) or by transfection with the human gene encoding P-gp (L1210/T), we have previously described cross-resistance to tunicamycin (TNM), a protein N-glycosylation inhibitor. Here we studied whether this cross-resistance ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2016039
更新日期：2016-10-01 00:00:00
abstract：:The substantia gelatinosa of the trigeminal subnucleus caudalis has been considered to be an essential location for the transference of orofacial sensory signals. The co-localization of inhibitory and excitatory neurotransmitters in the same substantia gelatinosa (SG) neurons has demonstrated their essential part in t...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2019027
更新日期：2019-09-01 00:00:00
abstract：:7,8-Dihydroxyflavone (7,8-DHF) is a natural flavonoid compound that act as Trk-B agonist. 7,8-DHF is also a potent antioxidant. When applied systematically, 7,8-DHF can pass through blood-brain barrier and exhibit potential therapeutic effects in several animal models of neurodegenerative disorders. This study investi...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2020022
更新日期：2020-09-01 00:00:00
abstract：:A number of computational methods for the description of the ligand-receptor interaction that were developed in the past decade are reviewed in this paper. The central two sections introduce the methods that are already established as useful tools for the qualitative and quantitative description of ligand-receptor com...
journal_title：General physiology and biophysics
pub_type： 杂志文章,评审
doi：
更新日期：1999-09-01 00:00:00
abstract：:High Na+ + Ca2+ exchange rates comparable with those reported for crayfish striated muscle, rat heart and rat brain, were observed in locust striated muscle homogenates and membrane preparations. The Na(+)-Ca2+ exchange followed the 1st order kinetics with a Km value of 18 mumol.l-1 for Ca, the pH optimum was at 8, th...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
abstract：:Beat-to-beat variability of action potential duration (short-term variability, SV) is an intrinsic property of mammalian myocardium. Since the majority of agents and interventions affecting SV may modify also action potential duration (APD), we propose here the concept of relative SV (RSV), where changes in SV are nor...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2015019
更新日期：2016-01-01 00:00:00
abstract：:Semiserial sections of lung capillaries of seven rabbits were examined for megakaryocytes. Triads of serial sections of each lobe were examined, and megakaryocyte counts per cm2 were determined. Median megakaryocyte count was determined for each lobe. The lobal values were used to calculate the was determined for each...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1987-08-01 00:00:00
abstract：:Phosphorylation of P-glycoprotein (PGP) by some protein kinases may play an important role in the regulation of its drug transport activity, and may also be important for the development of multidrug resistance (MDR) phenotype. In the present study we investigated the expression of three groups of mitogen-activated pr...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1999-03-01 00:00:00
abstract：:This study was designed to investigate the possible effectiveness of chronic resveratrol administration on redox state, inflammatory mediators and apoptosis rate in diabetic rats. Male Wistar rats were divided into four groups (n = 6): normal control, diabetic control, normal rats treated with resveratrol, and diabeti...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2012_039
更新日期：2012-12-01 00:00:00
abstract：:Activated endothelial cells play a crucial role in the formation of new blood vessels, a process known as angiogenesis, which can underlie the development of several diseases. Different antiangiogenic therapies aimed against vascular endothelial growth factor (VEGF), the dominant pro-angiogenic cytokine, have been dev...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2018047
更新日期：2019-03-01 00:00:00
abstract：:Using spin-labeled fatty acid derivatives and maleimide, the effect of temperature on the structural state of various parts of the lipid bilayer of sarcoplasmic reticulum (SR) membranes and the segmental motion of the Ca-ATPase molecule were investigated. The mobility of the spin probes localized in the hydrophobic zo...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1986-10-01 00:00:00
abstract：:Sleep is considered as a physiological regulator in the body. Gamma-aminobutyric acid (GABA) is a neurotransmitter that modulates sleep and affects cardiac functions. We evaluated effects of acute sleep deprivation (SD) on cardiac hemodynamic parameters, expression of pro-inflammatory cytokines, and Heat shock protein...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017049
更新日期：2018-05-01 00:00:00
abstract：:The inhibition of sodium and potassium currents in frog myelinated fibres by ajmaline (AM) and its quaternary derivative, N-propyl ajmaline (NPA), depends on voltage-clamp pulses and the state of channel gating mechanisms. The permanently charged NPA and protonated AM interact only (or mainly) with open channels, whil...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1983-08-01 00:00:00
abstract：:Expression of the haptoglobin (Hp) gene is liver specific and acute phase (AP) responsive. It was previously shown that transcriptional induction process of the rat Hp gene during turpentine induced AP response has been mediated by the liver nucleoprotein p29 which was shown to be homologous to the HMG-1 chromatin-ass...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2001-12-01 00:00:00
abstract：:Gastric cancer (GC) is a high mortality disease. We studied the function and mechanism of long non-coding RNA prostate cancer-associated transcript 6 (lncRNA PCAT6) on cell proliferation and epithelial-mesenchymal transition (EMT) in GC cells. CCK-8, flow cytometry and colony formation assay were respectively used to ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2019044
更新日期：2020-01-01 00:00:00
