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Induction Method (induction + method)
Selected AbstractsThe Effect of Induction Method on Defibrillation Threshold and Ventricular Fibrillation Cycle LengthJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006ENDRE ZIMA M.D. Introduction: Since no clinical data are available on the comparison of the "shock on T-wave" and "high frequency burst" ventricular fibrillation (VF) induction modes during defibrillation threshold (DFT) testing, we aimed to compare these two methods during implantable cardioverter defibrillator implantation. Methods: The DFT was determined with a step-down protocol using biphasic, anodal polarity (100%, 40%, 20% voltage control) shocks. Patients were randomized: VF was induced by 50 Hz burst in group B (n = 45) and T-wave shock in group T (n = 41). The DFT was defined as the lowest energy level that terminated VF; confirmed DFT (DFTc) was defined as the minimal energy level that consecutively terminated VF twice. Success rate of DFTc was calculated during an intraindividual test for the alternate induction method. Results: A total of 546 episodes of VF were induced: n = 278 (B) vs n = 268 (T). Incidence of VT during inductions was 9.9% (B) vs 2.7% (T), P < 0.05. Neither the DFT, 8.8 ± 4.0 J (B) vs 9.7 ± 4.2 J (T), nor the DFTc, 10.6 ± 5.1 J (B) vs 10.8 ± 4.2 J (T), proved to be significantly different. A significant correlation was found between VF cycle length (CL) and the concomitant DFT (r = 0.298, P < 0.05) in group T only. Subgroup analysis of patients under chronic class III antiarrhythmic treatment showed no increase of the DFT in either group and significantly lower incidence of VT induction in group T regardless of antiarrhythmic treatment. Conclusion: The DFT and the VFCL proved to be independent of the VF induction method. The T-wave shock was more unlikely to induce VT during DFT testing. These results suggest that both methods are reliable in DFT determination, though T-wave shock application is a more reliable method for DFT testing. [source] Revisiting Intragastric Ethanol Intubation as a Dependence Induction Method for Studies of Ethanol Reward and Motivation in RatsALCOHOLISM, Issue 3 2010Simone Braconi Background:, The purpose of this study was to re-examine intragastric ethanol intubation as a dependence induction method that effectively induces physical dependence upon ethanol over a short time period, is devoid of intrinsic stress artifacts, inexpensive, and easy to implement. Methods:, Male Wistar rats were subjected to ethanol dependence induction via intragastric ethanol intubation. Ethanol solution (final concentration 20%, made up in a dietary liquid vehicle consisting of powdered milk, sucrose, and water) was intubated 4 times per day, at 4-hour intervals, for 6 consecutive days (for a total of 10 g/kg/day). The utility of this procedure was evaluated for inducing physical dependence, determined by daily and final withdrawal ratings. Anxiety-like behavior associated with ethanol dependence history was examined using the elevated plus-maze (EPM) test, conducted 5 days after ethanol withdrawal. To evaluate whether potential stress-like effects of intragastric intubation per se produce lasting effects on behavior, experimentally naive rats were compared with vehicle-intubated rats for anxiety-like behavior on the EPM. Results:, Blood alcohol levels reached stable levels between 200 and 250 mg%, measured 1 hour after the second and third ethanol intubation on days 2, 4, and 6. Ethanol-treated rats developed significant somatic withdrawal signs, recorded daily between 10 and 12 hours after the last ethanol administration. At 5 days postwithdrawal, ethanol-treated rats showed significant anxiety-like behavior, measured by decreased open arm time and open arm entries on the EPM, compared with vehicle controls. Additionally, ethanol postdependent rats showed decreased open arm time compared with experimentally naive rats. EPM performance did not differ between vehicle-intubated and naive rats. No withdrawal seizures were observed and mortality rate was near zero. Conclusions:, These findings suggest that intragastric ethanol administration produces a behavioral profile consistent with ethanol dependence (i.e., significant withdrawal signs after termination of ethanol exposure and elevated anxiety-like behavior persisting beyond completion of physical withdrawal), and that the intubation procedure itself does not produce lasting nonspecific anxiety-like effects. Thus, under the conditions employed here, this procedure provides an effective tool for inducing and evaluating the consequences of ethanol dependence in animal models of ethanol reward and motivation. [source] The Effect of Induction Method on Defibrillation Threshold and Ventricular Fibrillation Cycle LengthJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006ENDRE ZIMA M.D. Introduction: Since no clinical data are available on the comparison of the "shock on T-wave" and "high frequency burst" ventricular fibrillation (VF) induction modes during defibrillation threshold (DFT) testing, we aimed to compare these two methods during implantable cardioverter defibrillator implantation. Methods: The DFT was determined with a step-down protocol using biphasic, anodal polarity (100%, 40%, 20% voltage control) shocks. Patients were randomized: VF was induced by 50 Hz burst in group B (n = 45) and T-wave shock in group T (n = 41). The DFT was defined as the lowest energy level that terminated VF; confirmed DFT (DFTc) was defined as the minimal energy level that consecutively terminated VF twice. Success rate of DFTc was calculated during an intraindividual test for the alternate induction method. Results: A total of 546 episodes of VF were induced: n = 278 (B) vs n = 268 (T). Incidence of VT during inductions was 9.9% (B) vs 2.7% (T), P < 0.05. Neither the DFT, 8.8 ± 4.0 J (B) vs 9.7 ± 4.2 J (T), nor the DFTc, 10.6 ± 5.1 J (B) vs 10.8 ± 4.2 J (T), proved to be significantly different. A significant correlation was found between VF cycle length (CL) and the concomitant DFT (r = 0.298, P < 0.05) in group T only. Subgroup analysis of patients under chronic class III antiarrhythmic treatment showed no increase of the DFT in either group and significantly lower incidence of VT induction in group T regardless of antiarrhythmic treatment. Conclusion: The DFT and the VFCL proved to be independent of the VF induction method. The T-wave shock was more unlikely to induce VT during DFT testing. These results suggest that both methods are reliable in DFT determination, though T-wave shock application is a more reliable method for DFT testing. [source] An osmotic induction method for externally marking saltwater fishes, Stigmatopora argus and Stigmatopora nigra, with calceinJOURNAL OF FISH BIOLOGY, Issue 4 2010J. E. Smith Calcein marking via osmotic induction and overnight immersion was compared in saltwater fishes. Immersion in a salt solution for 10 min followed by 30 min in a 500 mg l,1 calcein solution produced the highest fluorescent mark in 40 min with no effect on survival. [source] Revisiting Intragastric Ethanol Intubation as a Dependence Induction Method for Studies of Ethanol Reward and Motivation in RatsALCOHOLISM, Issue 3 2010Simone Braconi Background:, The purpose of this study was to re-examine intragastric ethanol intubation as a dependence induction method that effectively induces physical dependence upon ethanol over a short time period, is devoid of intrinsic stress artifacts, inexpensive, and easy to implement. Methods:, Male Wistar rats were subjected to ethanol dependence induction via intragastric ethanol intubation. Ethanol solution (final concentration 20%, made up in a dietary liquid vehicle consisting of powdered milk, sucrose, and water) was intubated 4 times per day, at 4-hour intervals, for 6 consecutive days (for a total of 10 g/kg/day). The utility of this procedure was evaluated for inducing physical dependence, determined by daily and final withdrawal ratings. Anxiety-like behavior associated with ethanol dependence history was examined using the elevated plus-maze (EPM) test, conducted 5 days after ethanol withdrawal. To evaluate whether potential stress-like effects of intragastric intubation per se produce lasting effects on behavior, experimentally naive rats were compared with vehicle-intubated rats for anxiety-like behavior on the EPM. Results:, Blood alcohol levels reached stable levels between 200 and 250 mg%, measured 1 hour after the second and third ethanol intubation on days 2, 4, and 6. Ethanol-treated rats developed significant somatic withdrawal signs, recorded daily between 10 and 12 hours after the last ethanol administration. At 5 days postwithdrawal, ethanol-treated rats showed significant anxiety-like behavior, measured by decreased open arm time and open arm entries on the EPM, compared with vehicle controls. Additionally, ethanol postdependent rats showed decreased open arm time compared with experimentally naive rats. EPM performance did not differ between vehicle-intubated and naive rats. No withdrawal seizures were observed and mortality rate was near zero. Conclusions:, These findings suggest that intragastric ethanol administration produces a behavioral profile consistent with ethanol dependence (i.e., significant withdrawal signs after termination of ethanol exposure and elevated anxiety-like behavior persisting beyond completion of physical withdrawal), and that the intubation procedure itself does not produce lasting nonspecific anxiety-like effects. Thus, under the conditions employed here, this procedure provides an effective tool for inducing and evaluating the consequences of ethanol dependence in animal models of ethanol reward and motivation. [source] Titrated low-dose vaginal and/or oral misoprostol to induce labour for prelabour membrane rupture: a randomised trialBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2008L Bricker Objective, To evaluate the clinical effectiveness and safety of titrated low-dose misoprostol for induction of labour (IOL) in the presence of prelabour rupture of membranes (PROM). Design, Randomised controlled trial. Setting, Maternity units in the UK (9) and Egypt (1). Population, Women >34 weeks of gestation with PROM, singleton viable fetus and no previous caesarean section. Methods, Subjects randomised to IOL with a titrated low-dose misoprostol regimen (oral except if unfavourable cervix, where initial dose vaginal) or a standard induction method, namely vaginal dinoprostone followed by intravenous oxytocin if the cervix was unfavourable or intravenous oxytocin alone if the cervix was favourable. Main outcome measures, Primary outcome measures were caesarean section and failure to achieve vaginal delivery within 24 hours. Analysis was by intention to treat. Results, The trial did not achieve the planned sample size of 1890 due to failure in obtaining external funding. Seven hundred and fifty-eight women were randomised (375 misoprostol and 383 standard). There were less caesarean section (14 versus 18%, relative risk [RR] 0.79; 95% CI 0.57,1.09) and less women who failed to achieve vaginal delivery within 24 hours in the misoprostol group (24 versus 31%, RR 0.79; 95% CI 0.63,1.00), but the differences were not statistically significant. Subgroup analysis showed that with unfavourable cervix, misoprostol may be more effective than vaginal dinoprostone. There was no difference in hyperstimulation syndrome. There were more maternal adverse effects with misoprostol, but no significant differences in maternal and neonatal complications. Conclusions, Titrated low-dose misoprostol may be a reasonable alternative for IOL in the presence of PROM, particularly in women with an unfavourable cervix. Safety and rare serious adverse events could not be evaluated in a trial of this size. [source] 2121: Sustained neuroprotection after a single intravitreal injection of PGJ2 in a rodent model of NAIONACTA OPHTHALMOLOGICA, Issue 2010V TOUITOU Purpose Prostaglandin-J2 (PGJ2) has been proposed as a potential neuroprotective agent. We wanted to evaluate the toxicity/efficacy of a single intravitreal (IVT) injection of PGJ2 in a rodent model of nonarteritic anterior ischemic optic neuropathy (NAION). Methods We used the laser-activated rose Bengal induction method to produce AION in Long-Evans rats. We evaluated IVT-PGJ2 retinal and ON toxicity. Following induction, PGJ2 was IVT-injected in the treatment-group. IVT phosphate-buffered-saline (PBS) was used as control. Functional studies (VEP) were performed at baseline and at 7days post-treatment. Structural studies included immunohistochemical (IHC), electron microscopic (EM) analysis of the optic nerve (ON), and stereologic analysis of retinal ganglion cell (RGC) numbers at30 day 30. Results Toxicity: IVT PGJ2 (5 eyes) did not induce any significant functional/structural changes in the retina or ON of treated animals compared with animals injected with PBS (5 eyes) 30 days post-injection. Efficacy: After a single IVT-injection, day7 VEPs in the PGJ2-treatment group (n=7) had amplitudes 103.6% of baseline, whereas the PBS-treated group (n=6) had VEPs that were 42.4% of the baseline. 30days post-stroke, EM of ON from the treatment-group demonstrated significant preservation of axons and decreased demyelination. Stereological RGCcounts confirmed significant (p<0.04) RGC preservation in PGJ2-treated animals (1462.6 cells/µm2) compared w the stroke+PBS group (1156.5 cells/µm2). Conclusion A single IVT of PGJ2 preserves RGCs and their axons, and provides sustained neuroprotection for at least 1 month following initial ischemic event. [source] | ||||||||||