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Hz Frequency (hz + frequency)
Selected AbstractsEfficacy of repetitive transcranial magnetic stimulation in alcohol dependence: a sham-controlled studyADDICTION, Issue 1 2010Biswa R. Mishra ABSTRACT Objective To study the anticraving efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) of the right dorsolateral pre-frontal cortex (DLPFC) in patients with alcohol dependence. Methods We performed a prospective, single-blind, sham-controlled study involving 45 patients with alcohol dependence syndrome (according to ICD-10 DCR), with Clinical Institute of Withdrawal Assessment in Alcohol Withdrawal (CIWA-Ar) scores ,10. Patients were allocated to active and sham rTMS in a 2 : 1 ratio, such that 30 patients received active and 15 patients sham rTMS to the right DLPFC (10 Hz frequency, 4.9 seconds per train, inter-train interval of 30 seconds, 20 trains per session, total 10 sessions). The Alcohol Craving Questionnaire (ACQ-NOW) was administered to measure the severity of alcohol craving at baseline, after the last rTMS session and after 1 month of the last rTMS session. Results Two-way repeated-measures analysis of variance (ANOVA) showed significant reduction in the post-rTMS ACQ-NOW total score and factor scores in the group allocated active rTMS compared to the sham stimulation. The effect size for treatment with time interaction was moderate (,2 = 0.401). Conclusions Right dorsolateral pre-frontal high-frequency rTMS was found to have significant anticraving effects in alcohol dependence. The results highlight the potential of rTMS which, combined with other anticraving drugs, can act as an effective strategy in reducing craving and subsequent relapse in alcohol dependence. [source] Electrical activation of the orbicularis oculi muscle does not increase the effectiveness of botulinum toxin type A in patients with blepharospasmEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2010A. Conte Background:, Our primary aim in this study was to determine whether electrically induced activation of the injected muscle increases effectiveness of botulinum type A toxin (BonT-A) in patients with blepharospasm (BPS). The second aim was to assess the safety of BonT-A by investigating whether BonT-A injection alters the excitability of blink reflex circuits in the brainstem. Methods:, Twenty-three patients with BPS received BonT-A (Botox) injected bilaterally into the orbicularis oculi muscle at a standard dose. In 18 patients, electrically induced muscle activation of the orbicularis oculi muscle on one side was performed for 60 min (4 Hz frequency) in a single session, immediately after BonT-A injection and in five patients for 60 min once a day for five consecutive days. The severity of BPS was assessed clinically with the BPS score. Compound muscle action potential (cMAPs) from the orbicularis oculi muscles were measured bilaterally. The blink reflex recovery cycle was studied at interstimulus intervals of 250 and 500 ms. Participants underwent clinical and neurophysiological assessment before BonT-A injection (T0) and 2 weeks thereafter (T1). Results:, Compound muscle action potential amplitude significantly decreased at T1 but did not differ between stimulated and non-stimulated orbicularis oculi in the two groups. BonT-A injection left the blink reflex recovery cycle tested on the stimulated and non-stimulated sides unchanged. Conclusions:, In patients with BPS, the electrically induced muscle activation neither increases the effectiveness of BonT-A nor produces larger electrophysiological peripheral effects. The lack of BonT-A-induced changes in the blink reflex recovery cycle provides evidence that BonT-A therapy is safe in patients with BPS. [source] Effect of Er:YAG laser and EDTAC on the adhesiveness to dentine of different sealers containing calcium hydroxideINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2003F. Picoli Abstract Aim, To evaluate the effect of 15% EDTAC solution and Er:YAG laser irradiation on the adhesiveness to dentine of root canal sealers containing calcium hydroxide. Methodology, The crowns of 60 maxillary human molars were ground until dentine was exposed. The teeth were divided into three groups of 20 teeth: group I, the dentine surface received no treatment; group II, 15% EDTAC solution was applied to the dentine; group III, the dentine received Er:YAG laser application (11 mm focal distance with perpendicular incidence to dentine surface; 4 Hz frequency; 200 mJ energy; 2.25 W potency; 62 J total energy; 1 min application time). Aluminium cylinders filled with the sealers, Sealer 26, Apexit, Sealapex and CRCS, were then applied to the treated surfaces. Adhesiveness was measured with a universal testing machine, with traction results given in MegaPascals (MPa). These results were submitted to anova tests. Results, Statistical analysis showed significant differences (P < 0.01) amongst adhesiveness values of the sealers and treatments tested. Thus, sealers could be ranked in decreasing adhesiveness values: Sealer 26, CRCS, Apexit, Sealapex. Er:YAG laser irradiation and EDTAC solution application increased adhesiveness values only for Sealer 26 and Apexit. Laser irradiation was superior to EDTAC application only for Sealer 26 adhesiveness values. Conclusions, Er:YAG laser is as efficient as EDTAC solution in increasing adhesiveness of root canal sealers containing calcium hydroxide to human dentine. [source] Mechanical strain increases cytokine and chemokine production in bronchial fibroblasts from asthmatic patientsALLERGY, Issue 1 2009F. Le Bellego Background:, Mechanical strain and cytokine stimulation are two important mechanisms leading to airway remodeling in asthma. The effect of mechanical strain on cytokine secretion in airway fibroblasts is not known. The aim of this study was to determine whether bronchial and nasal fibroblasts differentially alter cytokine secretion in response to mechanical strain. Methods:, We measured secretion of the pro-fibrotic cytokine, interleukin-6 (IL-6), and the pro-inflammatory cytokines, IL-8 and monocyte chemotactic protein 1, before and after mechanical strain in bronchial fibroblasts obtained from asthmatic patients [asthmatic bronchial fibroblasts (BAF)] and normal volunteers [normal bronchial fibroblasts (BNF)], and in nasal fibroblasts (NF) obtained from nasal polyps. Cells were grown on flexible membranes and a mechanical strain of 30% amplitude, 1 Hz frequency was applied for 3, 6 and 24 h. Control cells were unstrained. IL-6, IL-8 and monocyte chemotactic protein 1 was measured after 24 h strain using enzyme-linked immunoassay; mRNA was measured by real time polymerase chain reaction. We also measured mRNA for versican, a matrix proteoglycan, known to be upregulated in the asthmatic airway wall. Results:, In unstrained conditions, no differences in cytokine secretion were observed. After 24 h strain, BAF secreted more IL-6 than BNF. Mechanical strain increased IL-8 mRNA in BAF, BNF and NF; and IL-6 and versican mRNA, in BAF, only. Conclusions:, Cytokine responses to mechanical strain varied in different airway fibroblast populations, and depended on the site of origin, and the underlying inflammatory state. Strain resulted in IL-6 upregulation and increased message for extracellular matrix protein in bronchial fibroblasts from asthmatic patients only, and may reflect these patients' propensity for airway remodeling. [source] Dynamic mechanical behavior of LCP fiber/glass fiber,reinforced LLDPE compositesPOLYMER COMPOSITES, Issue 2 2001S. A. R. Hashmi Liquid crystalline polymer (LCP) fibers and glass fibers have been used to rein force linear low density polyethylene (LLDPE) by using an elastic melt extruder and the compression molding technique. The impact behavior of hybrid composites of different composition is compared and is explained on the basis of the volume frac tion of the fibers. Addition of glass fibers decreases the Izod impact strength LLDPE. The impact strength of the composites increases when glass fibers are placed by LCP fibers. Dynamic mechanical , and , relaxations are studied and effect of variation of fiber composition on these relaxations is reported in the tem perature range from ,50 to 150°C at 1 Hz frequency, a relaxation shifts toward higher temperatures with addition of fibers in LLDPE. Addition of fibers increases the storage modulus of LLDPE. [source] Intraoperative Assessment of an Implantable Electrode Array for Cavernous Nerve StimulationTHE JOURNAL OF SEXUAL MEDICINE, Issue 8 2008Arthur L. Burnett ABSTRACT Introduction., Erectile dysfunction remains a major functional complication of radical prostatectomy in the modern era despite surgical techniques to preserve the penile autonomic nerve supply. Aim., To develop and evaluate a neurostimulation system for cavernous nerve electrical stimulation for future use as a chronic implantation device that neurotrophically promotes erectile function recovery following radical prostatectomy. Method., After radical retropubic prostatectomy, the neurovascular bundle was stimulated using a temporarily placed electrode array of an implantable neurostimulation system (20 Hz frequency, 260 µ seconds pulse width, 5 mA,60 mA amplitude up to 10 minutes), and penile circumference increases were measured. Main Outcome Measure., Increase in penile circumference. Results., Among 12 men (mean age 60.3 years) enrolled in this study, 6 (50%) demonstrated measurable increases in penile circumference in response to cavernous nerve stimulation. Among these six men, the mean increase was 5.0 mm (range 1.6 mm to 7.0 mm). Temporary surgical placement of the device was done with relative ease, and there was no evidence of injury to the neurovascular bundle. Conclusions., A chronic implantable nerve stimulation system for cavernous nerve stimulation having possible neuromodulatory effects on the recovery of penile erections after radical prostatectomy is feasible. Burnett AL, Teloken PE, Briganti A, Whitehurst T, and Montorsi F. Intraoperative assessment of an implantable electrode array for cavernous nerve stimulation. J Sex Med 2008;5:1949,1954. [source] Sinusoidal ELF magnetic fields affect acetylcholinesterase activity in cerebellum synaptosomal membranesBIOELECTROMAGNETICS, Issue 4 2010Silvia Ravera Abstract The effects of extremely low frequency magnetic fields (ELF-MF) on acetylcholinesterase (AChE) activity of synaptosomal membranes were investigated. Sinusoidal fields with 50,Hz frequency and different amplitudes caused AChE activity to decrease about 27% with a threshold of about 0.74,mT. The decrease in enzymatic activity was independent of the time of permanence in the field and was completely reversible. Identical results were obtained with exposure to static MF of the same amplitudes. Moreover, the inhibitory effects on enzymatic activity are spread over frequency windows with different maximal values at 60, 200, 350, and 475,Hz. When synaptosomal membranes were solubilized with Triton, ELF-MF did not affect AChE activity, suggesting the crucial role of the membrane, as well as the lipid linkage of the enzyme, in determining the conditions for inactivation. The results are discussed in order to give an interpretation at molecular level of the macroscopic effects produced by ELF-MF on biological systems, in particular the alterations of embryo development in many organisms due to acetylcholine accumulation. Bioelectromagnetics 31:270,276, 2010. © 2009 Wiley-Liss, Inc. [source] | ||||||||||