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Muscle Relaxation (muscle + relaxation)
Kinds of Muscle Relaxation Selected AbstractsProgressive muscle relaxation, breathing exercises, and ABC relaxation theoryJOURNAL OF CLINICAL PSYCHOLOGY, Issue 12 2001Mia Matsumoto This study compared the psychological effects of Progressive Muscle Relaxation (PMR) and breathing exercises. Forty-two students were divided randomly into two groups and taught PMR or breathing exercises. Both groups practiced for five weeks and were given the Smith Relaxation States Inventory before and after each session. As hypothesized, PMR practitioners displayed greater increments in relaxation states (R-States) Physical Relaxation and Disengagement, while breathing practitioners displayed higher levels of R-State Strength and Awareness. Slight differences emerged at Weeks 1 and 2; major differences emerged at Weeks 4 and 5. A delayed and potentially reinforcing aftereffect emerged for PMR only after five weeks of training,increased levels of Mental Quiet and Joy. Clinical and theoretical implications are discussed. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1551,1557, 2001. [source] Control of muscle blood flow during exercise: local factors and integrative mechanismsACTA PHYSIOLOGICA, Issue 4 2010I. Sarelius Abstract Understanding the control mechanisms of blood flow within the vasculature of skeletal muscle is clearly fascinating from a theoretical point of view due to the extremely tight coupling of tissue oxygen demands and blood flow. It also has practical implications as impairment of muscle blood flow and its prevention/reversal by exercise training has a major impact on widespread diseases such as hypertension and diabetes. Here we analyse the role of mediators generated by skeletal muscle activity on smooth muscle relaxation in resistance vessels in vitro and in vivo. We summarize their cellular mechanisms of action and their relative roles in exercise hyperaemia with regard to early and late responses. We also discuss the consequences of interactions among mediators with regard to identifying their functional significance. We focus on (potential) mechanisms integrating the action of the mediators and their effects among the cells of the intact arteriolar wall. This integration occurs both locally, partly due to myoendothelial communication, and axially along the vascular tree, thus enabling the local responses to be manifest along an entire functional vessel path. Though the concept of signal integration is intriguing, its specific role on the control of exercise hyperaemia and the consequences of its modulation under physiological and pathophysiological conditions still await additional analysis. [source] Estimation of endogenous adenosine activity at adenosine receptors in guinea-pig ileum using a new pharmacological methodACTA PHYSIOLOGICA, Issue 2 2010K. F. Nilsson Abstract Aim:, Adenosine modulates neurotransmission and in the intestine adenosine is continuously released both from nerves and from smooth muscle. The main effect is modulation of contractile activity by inhibition of neurotransmitter release and by direct smooth muscle relaxation. Estimation of adenosine concentration at the receptors is difficult due to metabolic inactivation. We hypothesized that endogenous adenosine concentrations can be calculated by using adenosine receptor antagonist and agonist and dose ratio (DR) equations. Methods:, Plexus-containing guinea-pig ileum longitudinal smooth muscle preparations were made to contract intermittently by electrical field stimulation in organ baths. Schild plot regressions were constructed with 2-chloroadenosine (agonist) and 8-(p -sulfophenyl)theophylline (8-PST; antagonist). In separate experiments the reversing or enhancing effect of 8-PST and the inhibiting effect of 2-chloroadenosine (CADO) were analysed in the absence or presence of an adenosine uptake inhibitor (dilazep), and nucleoside overflow was measured by HPLC. Results:, Using the obtained DR, baseline adenosine concentration was calculated to 28 nm expressed as CADO activity, which increased dose dependently after addition of 10,6 m dilazep to 150 nm (P < 0.05). HPLC measurements yielded a lower fractional increment (80%) in adenosine during dilazep, than found in the pharmacological determination (440%). Conclusion:, Endogenous adenosine is an important modulator of intestinal neuro-effector activity, operating in the linear part of the dose,response curve. Other adenosine-like agonists might contribute to neuromodulation and the derived formulas can be used to calculate endogenous agonist activity, which is markedly affected by nucleoside uptake inhibition. The method described should be suitable for other endogenous signalling molecules in many biological systems. [source] Limitations of relaxation kinetics on muscular workACTA PHYSIOLOGICA, Issue 2 2010J. McDaniel Abstract Aim:, Positive net work produced during cyclic contractions is partially limited by relaxation kinetics, which to date, have not been directly investigated. Therefore, the purpose of this investigation was to determine the influence of relaxation kinetics on cyclic work. Methods:, Soleus muscles of four cats were isolated and subjected to a series of work loops (0.5, 1, 1.5 and 2 Hz cycle frequencies) during which stimulation terminated prior to the end of the shortening phase to allow for complete muscle relaxation and matched discrete sinusoidal shortening contractions during which stimulation remained on until the completion of the shortening phase. Muscle length changes during these protocols were centred on optimum length and were performed across muscle lengths that represented walking gait. Results:, When muscle excursions were centred on Lo relaxation kinetics decreased muscular work by 2.8 ± 0.8%, 12.1 ± 4.1%, 27.9 ± 4.5% and 40.1 ± 5.9% for 0.5, 1, 1.5 and 2 Hz respectively. However, relaxation kinetics did not influence muscular work when muscle excursions represented walking gait. In addition, muscular work produced at muscle lengths associated with walking gait was less than the work produced across Lo (55.7 ± 20.0%, 53.5 ± 21.0%, and 50.1 ± 22.0% for 0.5, 1 and 1.5 Hz respectively). Conclusion:, These results imply that relaxation kinetics are an important factor that limit the ability of muscle to produce work; however, the influence of relaxation kinetics on physiological function may depend on the relation between the optimum length and natural excursion of a muscle. [source] Diversity of effective treatments of panic attacks: what do they have in common?,DEPRESSION AND ANXIETY, Issue 1 2010Walton T. Roth M.D. Abstract By comparing efficacious psychological therapies of different kinds, inferences about common effective treatment mechanisms can be made. We selected six therapies for review on the basis of the diversity of their theoretical rationales and evidence for superior efficacy: psychoanalytic psychotherapy, hypercapnic breathing training, hypocapnic breathing training, reprocessing with and without eye-movement desensitization, muscle relaxation, and cognitive behavior therapy. The likely common element of all these therapies is that they reduce the immediate expectancy of a panic attack, disrupting the vicious circle of fearing fear. Modifying expectation is usually regarded as a placebo mechanism in psychotherapy, but may be a specific treatment mechanism for panic. The fact that this is seldom the rationale communicated to the patient creates a moral dilemma: Is it ethical for therapists to mislead patients to help them? Pragmatic justification of a successful practice is a way out of this dilemma. Therapies should be evaluated that deal with expectations directly by promoting positive thinking or by fostering non-expectancy. Depression and Anxiety, 2010. Published 2009 Wiley-Liss, Inc. [source] Effects of an occlusal splint compared with cognitive-behavioral treatment on sleep bruxism activityEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2007Michelle A. Ommerborn The impact of an occlusal splint (OS) compared with cognitive-behavioral treatment (CBT) on the management of sleep bruxism (SB) has been poorly investigated. The aim of this study was to evaluate the efficacy of an OS with CBT in SB patients. Following a randomized assignment, the OS group consisted of 29, and the CBT group of 28, SB patients. The CBT comprised problem-solving, progressive muscle relaxation, nocturnal biofeedback, and training of recreation and enjoyment. The treatment took place over a period of 12 wk, and the OS group received an OS over the same time period. Both groups were examined pretreatment, post-treatment, and at 6 months of follow-up for SB activity, self-assessment of SB activity and associated symptoms, psychological impairment, and individual stress-coping strategies. The analyses demonstrated a significant reduction in SB activity, self-assessment of SB activity, and psychological impairment, as well as an increase of positive stress-coping strategies in both groups. However, the effects were small and no group-specific differences were seen in any dependent variable. This is an initial attempt to compare CBT and OS in SB patients, and the data collected substantiate the need for further controlled evaluations, using a three-group randomized design with repeated measures to verify treatment effects. [source] The design of supervisory rule-based control in the operating theatre via an anaesthesia simulatorEXPERT SYSTEMS, Issue 1 2002M. Mahfouf The development of online drug administration strategies in operating theatres represents a highly safety-critical situation. The usefulness of different levels of simulation prior to clinical trials has been shown in previous studies in muscle relaxant anaesthesia. Thus, in earlier work on predictive self-tuning control for muscle relaxation a dual computer real-time simulation was undertaken, subsequent to algorithm validation via off-line simulation. In the present approach a supervised rule-based control algorithm is used. The control software was implemented on the actual machine to be used in theatre, while another computer acted as a real-time patient simulator. This set-up has further advantages of providing accurate timing and also finite data accuracy via the ADC/DAC interface, or the equivalent digital lines. Also, it provides for controller design fast simulation studies compared to the real-time application. In this paper, a new architecture which combines several hierarchical levels for control (a Mamdani-type fuzzy controller), adaptation (self-organizing fuzzy logic control) and performance monitoring (fault detection, isolation and accommodation) is developed and applied to a computer real-time simulation platform for muscle relaxant anaesthesia. Experimental results showed that the proposed algorithm fulfilled successfully the requirements for autonomy, i.e. automatic control, adaptation and supervision, and proved effective in dealing with the faults and disturbances which are normally encountered in operating theatres during surgery. [source] Phentolamine mesylate relaxes rabbit corpus cavernosum by a nonadrenergic, noncholinergic mechanismFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2001Subbarao Vemulapalli The contribution of NO-cGMP dependent pathway to phentolamine mesylate-evoked nonadrenergic, noncholinergic relaxation of rabbit corpus cavernosum was investigated in vitro. Stimulation of nonadrenergic, noncholinergic neurons of the rabbit corpus cavernosum elicited frequency-related relaxation that was significantly attenuated by L-NAME (NO synthase inhibitor) or ODQ (an inhibitor of guanylate cyclase). Moreover, tetrodotoxin, a sodium channel blocker, abolished the electrical field stimulation-induced relaxation of rabbit corpus cavernosum, suggesting that neuronal release of NO mediates relaxation to electrical field stimulation. Phentolamine mesylate (30 and 100 nM) dose-dependently enhanced electrical field stimulation-induced relaxation of the rabbit corpus cavernosum. Prazosin (30 ,M) and yohimbine (30 ,M) failed to affect phentolamine mesylate-mediated nonadrenergic, noncholinergic rabbit penile smooth muscle relaxation, suggesting that phentolamine relaxes rabbit corpus cavernosum independent of ,-adrenergic receptor blockade. In contrast, pretreatment of the rabbit cavernosal strips with L-NAME significantly-attenuated electrical field stimulation produced relaxations to phentolamine mesylate, suggesting that phentolamine mesylate relaxes rabbit corpus cavernosum by activating NO synthase. The data suggest that phentolamine mesylate relaxes nonadrenergic noncholinergic neurons of the rabbit corpus cavernosum by activating NO synthase and is independent of ,-adrenergic receptor blockade. [source] Synaptic Transmission: Inhibition of Neurotransmitter Release by Botulinum ToxinsHEADACHE, Issue 2003Oliver Dolly MSc Botulinum toxin type A, a protein long used in the successful treatment of various dystonias, has a complex mechanism of action that results in muscle relaxation. At the neuromuscular junction, the presynaptic nerve ending is packed with synaptic vesicles filled with acetylcholine, and clustered at the tip of the folds of the postsynaptic muscle membrane are the acetylcholine receptors. Synaptic vesicles fuse with the membrane in response to an elevation of intraneuronal calcium concentration and undergo release of their transmitter by exocytosis. Intracellular proteins that contribute to the fusion of the vesicles with the plasma membrane during exocytosis include synaptosomal protein with a molecular weight of 25 kDa (SNAP-25); vesicle-associated membrane protein (VAMP), also known as synaptobrevin; and syntaxin. Through their proteolytic action on these proteins, botulinum toxins prevent exocytosis, thereby inhibiting the release of acetylcholine. There are 7 serotypes of this toxin,A, B, C1, D, E, F, and G,and each cleaves a different intracellular protein or the same target at distinct bonds. The separate cleavage sites in SNAP-25 for botulinum toxin types A and E contribute to their dissimilar durations of muscle relaxation. This report describes the molecular basis for the inhibition by botulinum toxins of neuroexocytosis and subsequent functional recovery at the neuromuscular junction. [source] Review of systematic reviews about the efficacy of non-pharmacological interventions to improve sleep quality in insomniaINTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 4 2009Gerrit J De Niet MSc RN Abstract Background, Insomnia is a very common condition in various populations. Non-pharmacological interventions might offer (safe) alternatives for hypnotics. Aim, To evaluate the evidence for efficacy from systematic reviews about non-pharmacological interventions to improve sleep quality in insomnia by a systematic review of systematic reviews and meta-analyses. Search strategy, Search strategies were conducted in the Database of Abstracts of Reviews of Effects (2002,July 2008), The Cochrane Database of Systematic Reviews (2000,July 2008) and PubMed (1950,July 2008). Sleep quality was the outcome measure of interest. Selection criteria, Systematic reviews about the efficacy of one or more non-pharmacological interventions for insomnia, concerning both adult and elderly populations, were included. Reviews that included studies performed among populations suffering with severe neurological or cognitive impairments or with addictive disorders were excluded. Data analysis, Relevant data were extracted. The quality of the reviews found was appraised by using the Overview Quality Assessment Questionnaire. The evidence was appraised and divided into six classes. Results and conclusions, Sixteen reviews about 17 interventions were included. Six reviews were of adequate methodological quality. Of these, only one provided an effect size: a moderate effect was found for music-assisted relaxation. Weak evidence indicating a large effect was found for multicomponent cognitive behavioural therapy, progressive muscle relaxation, stimulus control and ,behavioural only'. Weak evidence indicating a moderate effect was found for paradoxical intention. Finally, weak evidence indicating a moderate to large effect was found for relaxation training. Because of the lack of sufficient methodological quality and the lack of calculated effect sizes, most of the included reviews were not suitable for drawing rigorous conclusions about the effect of non-pharmacological interventions on sleep quality in insomniacs. The non-pharmacological treatment of insomnia would benefit from renewed reviews based on a rigorous methodological approach. [source] The management of severe dental phobia in an adolescent boy: a case reportINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 4 2000J. Levitt Dental fear is a widespread problem that represents one of the major barriers to dental care. This report describes a case study of a 12-year-old boy who presented with dental phobia characterized as ,fear of catastrophe', ,generalized dental fear' and ,fear of specific stimuli'. The referral came from his general dental practitioner who had been unable to carry out even the simplest dental procedure on him. The patient required prevention, conservation and root canal therapy. The case illustrates the use of physical strategies, including muscle relaxation and relaxation breathing; practice strategies, including graded exposure and cognitive strategies, combined with individual control methods and inhalation sedation to successfully complete the dental treatment plan. [source] Protease-Activated Receptors: A Means of Converting Extracellular Proteolysis into Intracellular SignalsIUBMB LIFE, Issue 6 2002E. J. Mackie Abstract Protease-activated receptors (PARs) mediate cellular responses to a variety of extracellular proteases. The four known PARs constitute a subgroup of the family of seven-transmembrane domain G protein-coupled receptors and activate intracellular signalling pathways typical for this family of receptors. Activation of PARs involves proteolytic cleavage of the extracellular domain, resulting in formation of a new N terminus, which acts as a tethered ligand. PAR-1, -3, and -4 are relatively selective for activation by thrombin whereas PAR-2 is activated by a variety of proteases, including trypsin and tryptase. Recent studies in mice genetically incapable of expressing specific PARs have defined roles for PAR-1 in vascular development, and for PAR-3 and -4 in platelet activation, which plays a fundamental role in blood coagulation. PAR-1 has also been implicated in a variety of other biological processes including inflammation, and brain and muscle development. Responses mediated by PAR-2 include contraction of intestinal smooth muscle, epithelium-dependent smooth muscle relaxation in the airways and vasculature, and potentiation of inflammatory responses. The area of PAR research is rapidly expanding our understanding of how cells communicate and control biological functions, in turn increasing our knowledge of disease processes and providing potential targets for therapeutic intervention. [source] The incidence of intra-operative awareness during general anesthesia in China: a multi-center observational studyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2009L. XU Background: The incidence of awareness in patients undergoing general anesthesia is 0.1,0.2% in Western countries. The medical literatures about awareness during general anesthesia are still rare in China, but some previous studies have reported a higher incidence (1.4,6%) of intra-operative awareness. To find out the reason why the incidence reported in China is much higher than that in Western countries, we performed a prospective, multicenter, non-randomized observational study to determine the true incidence of intra-operative awareness in China. Methods: This is a prospective, non-randomized descriptive cohort study that was conducted at 25 academic medical centers in China. Eleven thousand one hundred and eighty-five patients were interviewed by research staff for evaluation of awareness at the first and fourth day after general anesthesia with muscle relaxation. An independent blinded committee evaluated the responses and determined whether awareness occurred. Necessary data were collected for a binary logistic regression analysis. Results: Data from 11,101 patients were presented. Forty-six cases (0.41%) were reported as definite awareness and 47 additional cases (0.41%) as possible awareness. Three hundred and fifty-five patients (3.19%) had dreams during general anesthesia. Awareness was associated with increased American Society of Anesthesiologists (ASA) physical status, a previous anesthesia, and anesthesia methods of total intravenous anesthesia. Conclusion: The incidence of intra-operative awareness in China is approximately 0.41%, two to three times higher than that widely cited in Western countries. Inappropriately light anesthesia, and the population proportion of surgery and general anesthesia in China may account for the difference. (ClinicalTrials.gov Identifier, NCT00693875.) [source] Efficacy of progressive muscle relaxation training in reducing anxiety in patients with acute schizophreniaJOURNAL OF CLINICAL NURSING, Issue 15 2009Wen-Chun Chen Aim and objectives., The objective of this study was to examine the efficacy of progressive muscle relaxation training on anxiety in patients with acute schizophrenia. Background., Many empirical studies have found progressive muscle relaxation training beneficial in reducing the psychological effects of anxiety. Progressive muscle relaxation training is also effective in reducing the distress symptoms associated with the symptomatology of schizophrenia. Design., An experimental randomised controlled trial using repeated measures. Method., The study was designed to examine the effects of progressive muscle relaxation training on patients diagnosed with schizophrenia. Study participants were acute psychiatric inpatients in Taiwan. Eighteen patients were block randomised and then assigned to an experimental or control group. The experimental group received progressive muscle relaxation training and the control group received a placebo intervention. Results from the Beck anxiety inventory were compared between groups as a pretest before intervention, on day 11 of intervention and one week post-test after the intervention was completed. Changes in finger temperature were measured throughout the experiment. Results., The degree of anxiety improvement was significantly higher in the progressive muscle relaxation training group than in the control group after progressive muscle relaxation training intervention (p < 0·0001) and at follow-up (p = 0·0446; the mean BAI score fell from 16·4 pretest to ,5·8 post-test. After adjusting for the change in patient finger temperature, the mean change in temperature was significantly different between the two patient groups. The average body temperature increased significantly after applying the progressive muscle relaxation training to patients with schizophrenia. Conclusion., This study demonstrated that progressive muscle relaxation training can effectively alleviate anxiety in patients with schizophrenia. Relevance to clinical practice., Progressive muscle relaxation training is potentially an effective nursing intervention in the reduction of anxiety in patients diagnosed with schizophrenia, depending on the quality of their mental status at the time of intervention. Progressive muscle relaxation training is a useful intervention as it is proven to reduce anxiety levels across a spectrum of psychiatric disorders. [source] Progressive muscle relaxation, breathing exercises, and ABC relaxation theoryJOURNAL OF CLINICAL PSYCHOLOGY, Issue 12 2001Mia Matsumoto This study compared the psychological effects of Progressive Muscle Relaxation (PMR) and breathing exercises. Forty-two students were divided randomly into two groups and taught PMR or breathing exercises. Both groups practiced for five weeks and were given the Smith Relaxation States Inventory before and after each session. As hypothesized, PMR practitioners displayed greater increments in relaxation states (R-States) Physical Relaxation and Disengagement, while breathing practitioners displayed higher levels of R-State Strength and Awareness. Slight differences emerged at Weeks 1 and 2; major differences emerged at Weeks 4 and 5. A delayed and potentially reinforcing aftereffect emerged for PMR only after five weeks of training,increased levels of Mental Quiet and Joy. Clinical and theoretical implications are discussed. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1551,1557, 2001. [source] Comparison between intubation and the laryngeal mask airway in moderately obese adultsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009M. ZOREMBA Background: Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period. Methods: We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation, with the patient supine, in a 30° head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t -test analysis. Statistical significance was considered to be P<0.05. Results: Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA). Conclusions: In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function. [source] Functional morphology of the sonic apparatus in the fawn cusk-eel Lepophidium profundorum (Gill, 1863)JOURNAL OF MORPHOLOGY, Issue 11 2007Michael L. Fine Abstract Recent reports of high frequency sound production by cusk-eels cannot be explained adequately by known mechanisms, i.e., a forced response driven by fast sonic muscles on the swimbladder. Time to complete a contraction-relaxation cycle places a ceiling on frequency and is unlikely to explain sounds with dominant frequencies above 1 kHz. We investigated sonic morphology in the fawn cusk-eel Lepophidium profundorum to determine morphology potentially associated with high frequency sound production and quantified development and sexual dimorphism of sonic structures. Unlike other sonic systems in fishes in which muscle relaxation is caused by internal pressure or swimbladder elasticity, this system utilizes antagonistic pairs of muscles: ventral and intermediate muscles pull the winglike process and swimbladder forward and pivot the neural arch (neural rocker) above the first vertebra backward. This action stretches a fenestra in the swimbladder wall and imparts strain energy to epineural ribs, tendons and ligaments connected to the anterior swimbladder. Relatively short antagonistic dorsal and dorsomedial muscles pull on the neural rocker, releasing strain energy, and use a lever advantage to restore the winglike process and swimbladder to their resting position. Sonic components grow isometrically and are typically larger in males although the tiny intermediate muscles are larger in females. Although external morphology is relatively conservative in ophidiids, sonic morphology is extremely variable within the family. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] Mind-Body Interventions During PregnancyJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 2 2008Amy E. Beddoe ABSTRACT Objective:, To examine published evidence on the effectiveness of mind-body interventions during pregnancy on perceived stress, mood, and perinatal outcomes. Data sources:, Computerized searches of PubMed, Cinahl, PsycINFO, and the Cochrane Library. Study Selection:, Twelve out of 64 published intervention studies between 1980 and February 2007 of healthy, adult pregnant women met criteria for review. Data extraction and synthesis:, Studies were categorized by type of mind-body modality used. Progressive muscle relaxation was the most common intervention. Other studies used a multimodal psychoeducation approach or a yoga and meditation intervention. The research contained methodological problems, primarily absence of a randomized control group or failure to adequately control confounding variables. Nonetheless, there was modest evidence for the efficacy of mind-body modalities during pregnancy. Treatment group outcomes included higher birthweight, shorter length of labor, fewer instrument-assisted births, and reduced perceived stress and anxiety. Conclusions:, There is evidence that pregnant women have health benefits from mind-body therapies used in conjunction with conventional prenatal care. Further research is necessary to build on these studies in order to predict characteristics of subgroups that might benefit from mind-body practices and examine cost effectiveness of these interventions on perinatal outcomes. [source] A Mechanism of Vasodilatory Action of Polyamines and Acetylpolyamines: Possible Involvement of their Ca2+ Antagonistic PropertiesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2000CHANG-SEON MYUNG Polyamines, a class of low-molecular weight organic polycations, have been shown to produce relaxing effects in vascular smooth muscles, although the mechanism has not been carefully examined. In this study, the mechanism of vascular action of polyamines and their metabolites, acetylpolyamines, was pharmacologically examined in the rabbit isolated thoracic aorta focusing on an endothelium-dependent component of vasodilatation and Ca2+ influx through plasma membrane channels. Both polyamines and acetylpolyamines (except N1 -acetylputrescine, which produced no response or very slight contraction) caused concentration-dependent relaxation in pre-constricted aortic rings containing an intact endothelium. Aortic rings denuded of endothelium were also responsive to both polyamines and acetylpolyamines. Inhibitors of nitric oxide (reduced haemoglobin and N, -nitro- l -arginine methyl ester), vasodilator prostaglandins (indomethacin) and guanylyl cyclase (methylene blue) did not affect the relaxation induced by both polyamines and acetylpolyamines in either endothelium-intact or -denuded aortic rings. Both polyamines and acetylpolyamines inhibited the concentration-dependent contraction for phenylephrine and K+. The Ca2+ agonist Bay K 8644 induced concentration-dependent contraction in segments of rabbit aorta partially depolarized with 15 mm KCl, and both polyamines and acetylpolyamines relaxed the Bay K 8644-induced contraction in a concentration-dependent manner. Interestingly, both polyamines and acetylpolyamines also decreased contractions evoked by the Ca2+ ionophore A23187. The concentration-response curve to exogenous Ca2+ in K+ -depolarization medium (K+ = 120 mm) was shifted to the right by both polyamines and acetylpolyamines. The response elicited by Ca2+ was increased by Bay K 8644 (10,6m), and this potentiation was also inhibited by both polyamines and acetylpolyamines. The results indicate that both polyamines and acetylpolyamines can induce vasorelaxation of rabbit thoracic aorta by an endothelium-independent mechanism in-vitro and relax vascular smooth muscle by acting at the plasma membrane level, decreasing the influx of Ca2+. Therefore, polyamines and acetylpolyamines may have Ca2+ antagonistic properties which may, in part, be involved in the mechanism of rabbit aortic vascular smooth muscle relaxation. [source] KATP channel openers: Structure-activity relationships and therapeutic potentialMEDICINAL RESEARCH REVIEWS, Issue 2 2004Raimund Mannhold Abstract ATP-sensitive potassium channels (KATP channels) are heteromeric complexes of pore-forming inwardly rectifying potassium channel subunits and regulatory sulfonylurea receptor subunits. KATP channels were identified in a variety of tissues including muscle cells, pancreatic ,-cells, and various neurons. They are regulated by the intracellular ATP/ADP ratio; ATP induces channel inhibition and MgADP induces channel opening. Functionally, KATP channels provide a means of linking the electrical activity of a cell to its metabolic state. Shortening of the cardiac action potential, smooth muscle relaxation, inhibition of both insulin secretion, and neurotransmitter release are mediated via KATP channels. Given their many physiological functions, KATP channels represent promising drug targets. Sulfonylureas like glibenclamide block KATP channels; they are used in the therapy of type 2 diabetes. Openers of KATP channels (KCOs), for example, relax smooth muscle and induce hypotension. KCOs are chemically heterogeneous and include as different classes as the benzopyrans, cyanoguanidines, thioformamides, thiadiazines, and pyridyl nitrates. Examples for new chemical entities more recently developed as KCOs include cyclobutenediones, dihydropyridine related structures, and tertiary carbinols. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 2, 213,266, 2004 [source] Bilateral occipital neuropathy as a rare complication of positioning for thyroid surgery in a morbidly obese patientACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2004S. Schulz-Stübner Background:, Peripheral neuropathies in various locations are described as complications after anesthesia and surgery. This is the first case report of temporary bilateral occipital neuropathy from positioning for thyroid surgery in a morbidly obese patient. Methods:, A 48-year-old women with a history of depression, fibro-myalgia, asthma, sleep apnea, diabetes mellitus and morbid obesity (127 kg, 165 cm) underwent 4 hours anesthesia with propofol/remifentanil without muscle relaxation for thyroid surgery. The neck with a very low range of motion secondary to fat tissue needed to be extended to facilitate surgery as much as possible. The head was carefully padded and there were no episodes of hypotension or hypoxemia throughout the case or in the PACU. At post op day 1 she complained of bilateral numbness in the distribution area of both greater occipital nerves. On post op day 2 tingling sensations and improvement of numbness was noticed. The patient recovered without residual symptoms after 6 weeks. Conclusion:, Pressure or shear stress to the nerve, hypoperfusion or metabolic disturbances are discussed as the leading etiology of nerve damage during surgery in the literature. Pressure from fat tissue during prolonged head extension for surgery seems to be the cause in this case and should therefore be avoided whenever possible in morbidly obese patients, especially when other risk factors for neuropathy like diabetes are present. [source] Vibration prolongs the cortical silent period in an antagonistic muscleMUSCLE AND NERVE, Issue 6 2009Christian Binder MD Abstract We tested whether the silent period, an indicator of inhibitory neuronal activity, is modulated by muscle vibration. Vibration was applied to the right extensor carpi radialis (ECR) muscle in 17 healthy subjects and, as a control experiment, to the dorsal terminal phalanges in 5 subjects. Data before vibration were compared with those during vibration. The cortical silent period (CSP) was evoked by transcranial magnetic stimuli (TMS) during voluntary wrist flexion or during voluntary wrist extension. TMS-evoked motor potentials (MEPs) of the flexor carpi radialis (FCR) muscle were recorded during muscle relaxation. The mixed nerve silent period (MNSP) was obtained by electrical stimulation of the median nerve during wrist flexion. ECR vibration induced a significant prolongation of the CSP in FCR. CSP increases induced by vibration of the dorsal terminal phalanges were significantly less pronounced. In ECR, the CSP tended to be shortened. MEPs and MNSP remained unchanged. We conclude that vibration enhances inhibitory neuronal properties in a non-vibrated antagonistic muscle, presumably at a supraspinal level. These results may be relevant for the treatment of spasticity of the upper extremity. Muscle Nerve, 2009 [source] Effect of transcranial magnetic stimulation on voluntary activation in patients with quadriceps weaknessMUSCLE AND NERVE, Issue 2 2005Dietmar Urbach MD Abstract Joint disease causes weakness and wasting of adjacent muscles, in part because of inability to fully activate these muscles voluntarily. Previous findings suggest that transcranial magnetic stimulation (TMS) paired with muscle contractions enhances maximal voluntary contraction force (MVC) in healthy subjects by improving voluntary activation (VA). The aim of the present study was to evaluate whether such an effect is also present in subjects suffering from diminished muscle force due to decreased VA. Three single TMS over resting motor threshold were applied in 10 patients with a mean age of 62 years after total-knee arthroplasty either during MVC or during muscle relaxation (control experiment) in a blinded randomized crossover study. MVC and VA were determined using a twitch-interpolation technique at 1, 15, 30, and 60 min after stimulation. There was a significant effect of TMS on MVC if applied in synchrony with muscle contraction, and this persisted for at least 60 min beyond stimulation. In patients suffering from joint disease, TMS might make physiotherapy more effective. Muscle Nerve, 2005 [source] The many faces of nitric oxide: cytotoxic, cytoprotective or bothNEUROGASTROENTEROLOGY & MOTILITY, Issue 7 2007J. W. Wiley Abstract, Nitric oxide (NO) has emerged as a major modulator of cellular function in health and disease. In addition to its well-known role as a mediator of smooth muscle relaxation, a rapidly developing body of research suggests, paradoxically, that NO can have both cytotoxic and cytoprotective effects. In this issue of Neurogastroenterology and Motility, Choi et al. provide evidence that supports NO has a prosurvival effect on interstitial cells of Cajal in the mouse stomach. The objective of this short review is to place this interesting report in the context of the current literature. [source] ,3 -Adrenoceptors in urinary bladder,,NEUROUROLOGY AND URODYNAMICS, Issue 6 2007Osamu Yamaguchi Abstract The ,-adrenoceptor (AR) is currently classified into ,1, ,2, and ,3 subtypes. A third subtype, ,3 -AR, was first identified in adipose tissue, but has also been identified in smooth muscle tissue, particularly in the gastrointestinal tract and urinary bladder smooth muscle. There is a predominant expression of ,3 -AR messenger RNA (mRNA) in human bladder, with 97% of total ,-AR mRNA being represented by the ,3 -AR subtype and only 1.5 and 1.4% by the ,1 -AR and , 2 -AR subtypes, respectively. Moreover, the presence of ,1 -, ,2 -, and ,3 -AR mRNAs in the urothelium of human bladder has been identified. The distribution of ,-AR subtypes mediating detrusor muscle relaxation is species dependent, the predominant subtype being the ,3 -AR in humans. Recent studies have suggested that cAMP-dependent routes are not exclusive mechanisms triggering the ,-AR-mediated relaxation of smooth muscle. It has been demonstrated in rats detrusor muscle that cAMP plays a greater role in ,-adrenergic relaxation against basal tone than against KCl-induced tone and that conversely calcium-activated K+ channels (BKca channels) play a greater role under the latter circumstances. In rat models, ,3 -AR agonists increase bladder capacity without influencing bladder contraction and have only weak cardiovascular side effects. Although this evidence points toward the clinical utility of ,3 -AR agonists as therapy for overactive bladder (OAB), pharmacological differences exist between rat and human ,3 -ARs. Development of compounds with high selectivity for the human ,3 -AR, identified by screening techniques using cell lines transfected with the human ,1 -, ,2 -, and ,3 -AR genes, may mitigate against such problems. The association between the tryptophan 64 arginine polymorphism in the ,3 -AR gene and idiopathic OAB is discussed. Neurourol. Urodynam. 26:752,756, 2007. © 2007 Wiley-Liss, Inc. [source] Gated dynamic 31P MRS shows reduced contractile phosphocreatine breakdown in mice deficient in cytosolic creatine kinase and adenylate kinaseNMR IN BIOMEDICINE, Issue 5 2009Hermien E. Kan Abstract We developed a new dedicated measurement protocol for dynamic 31P MRS analysis in contracting calf muscles of the mouse, using minimally invasive assessment of the contractile force combined with the acquisition of spectroscopic data gated to muscle contraction and determination of phosphocreatine (PCr) recovery rate and ATP contractile cost. This protocol was applied in a comparative study of six wild type (WT) mice and six mice deficient in cytosolic creatine kinase and adenylate kinase isoform 1 (MAK,/, mice) using 70 repeated tetanic contractions at two contractions per minute. Force levels during single contractions, and metabolite levels and tissue pH during resting conditions were similar in muscles of MAK,/, and WT mice. Strikingly, muscle relaxation after contraction was significantly delayed in MAK,/, mice, but during repeated contractions, the decrease in the force was similar in both mouse types. Gated data acquisition showed a negligible PCr breakdown in MAK,/, immediately after contraction, without a concomitant decrease in ATP or tissue pH. This protocol enabled the determination of rapid PCr changes that would otherwise go unnoticed due to intrinsic low signal-to-noise ratio (SNR) in mouse skeletal muscles combined with an assessment of the PCr recovery rate. Our results suggest that MAK,/, mice use alternative energy sources to maintain force during repeated contractions when PCr breakdown is reduced. Furthermore, the absence of large increases in adenosine diphosphate (ADP) or differences in force compared to WT mice in our low-intensity protocol indicate that creatine kinase (CK) and adenylate kinase (AK) are especially important in facilitating energy metabolism during very high energy demands. Copyright © 2009 John Wiley & Sons, Ltd. [source] Insertion characteristics, sealing pressure and fiberoptic positioning of CobraPLA in childrenPEDIATRIC ANESTHESIA, Issue 10 2007MAURIZIO PASSARIELLO MD Summary Background:, The CobraPLATM is a new supraglottic airway device designed for the use in spontaneously breathing and mechanically ventilated patients. In adults it has been found as effective as the LMA, but with better sealing qualities. The aim of the present study was to evaluate fit and sealing characteristics of CobraPLA size 1.5 and 2 in mechanically ventilated children. Methods:, Forty children, ASA I/II, aged 1,10 years, weighing 10,35 kg were scheduled for minor surgical procedures. The number of attempts for insertion and fiberoptic positioning of the CobraPLA was assessed. After muscle relaxation had been achieved, airway sealing pressure was measured by gradually increasing maximum inspiratory pressure to a maximum of 30 cmH2O. Results:, Insertion of CobraPLA was successful at the first attempt in 90% of patients. The vocal cords were visualized in 90% of patients (grade 0: 2.5%, grade 1: 7.5%, grade 2: 30%, grade 3: 15%, grade 4: 45%). Median sealing pressure was 20.0 ± 6.0 cmH2O. In 21% of patients gastric insufflation was observed at a peak inspiratory pressure of 20 cmH2O or below. Conclusions:, The CobraPLA was found to have easy insertion characteristics and good anatomical fitting in children between 10 and 35 kg. If positive pressure ventilation with CobraPLA size 1.5 and 2.0 is required, peak inspiratory pressure should be kept below the leak pressure and the abdomen closely monitored for signs of gastric insufflation. [source] Plasma ADMA concentrations at birth and mechanical ventilation in preterm infants: A prospective pilot studyPEDIATRIC PULMONOLOGY, Issue 12 2008Milan C. Richir MD Abstract Rationale Nitric oxide (NO) produced in the lung is an important mediator of normal lung development, vascular smooth muscle relaxation, and ventilation perfusion matching. NO is synthesized from arginine by the action of NO-synthase (NOS). Asymmetric dimethylarginine (ADMA), an endogenous derivate of arginine, inhibits NOS and is thereby a determinant of NO synthesis. We compared ADMA and arginine levels in preterm infants requiring mechanical ventilation with preterm infants who did not require mechanical ventilation and determined the relation between ADMA and the length of mechanical ventilation in these infants. Methods Thirty preterm infants, mean (SD) gestational age 29.3 (1.7) weeks and birth weight 1,340 (350) gram, of the Neonatal Intensive Care Unit of the VU University Medical Center were included. ADMA and arginine were measured in umbilical cord blood and the length of mechanical ventilation (days) was registered. Results Gestational age and birth weight were significantly smaller in infants requiring mechanical ventilation, but were not significantly correlated with plasma ADMA concentration after birth. Plasma ADMA concentrations were significantly higher in infants who required mechanical ventilation than in infants who did not require mechanical ventilation (1.53,±,0.23 and 1.37,±,0.14 µmol/L, respectively; P,=,0.036). ADMA concentration was significantly related to length of mechanical ventilation (B,=,3.4; 95% CI: 1.1,5.6; P,=,0.006), also after adjustment for gestational age (B,=,2.3; 95% CI: 0.4,4.2; P,=,0.024). Conclusions Preterm infants who require mechanical ventilation have increased ADMA levels compared to non-ventilated preterm infants. ADMA levels at birth are related to the length of mechanical ventilation. An increased ADMA concentration could reduce NO synthesis, which could lead to insufficient gas exchange and, consequently, a longer period of mechanical ventilation. Pediatr. Pulmonol. 2008; 43:1161,1166. © 2008 Wiley-Liss, Inc. [source] Contractile Changes of the Clitoral Cavernous Smooth Muscle in Female Rabbits with Experimentally Induced Overactive BladderTHE JOURNAL OF SEXUAL MEDICINE, Issue 5 2008Soon-Chul Myung MD ABSTRACT Introduction., Recently, growing clinical evidence has suggested that sexual dysfunction is more prevalent in women with overactive bladder (OAB). Aims., However, there has been no basic research to clarify the relationship between OAB and female sexual dysfunction. Therefore, we investigated this issue using a rabbit model of OAB. Methods., Twenty-seven New Zealand white female rabbits were randomly divided into the OAB and control groups. Main Outcome Measures., The contractile responses of clitoral cavernous strips to K+, phenylephrine (PE), Bay K 8644, and endothelin (ET)-1, and the relaxation responses of acetylcholine (ACh), sodium nitroprusside (SNP), and Y-27632 to PE-induced contraction by measuring isometric tension. Results., The contractile responses to K+, PE, Bay K 8644, and ET-1 were significantly more increased in the OAB group in a dose-dependant manner than in the control group (P < 0.05), and the responses to ET-1 were more prominent than those to the remaining substances (P < 0.01). The increased contractile responses to ET-1 were blocked by BQ123 (ETA receptor antagonist) but not by BQ788 (ETB receptor antagonist). Clitoral cavernosal strips from the OAB group were more difficult to relax than those from the control group in terms of ACh- and SNP-induced relaxation (P < 0.05). The Y-27632-induced relaxant responses to PE- and ET-1-induced contraction were less prominent in the OAB group than in the control group. Conclusions., The results of this study provide evidence that female OAB may deteriorate clitoral engorgement, which is associated with a greater force generation by increased calcium sensitization and subsequently decreased of relaxation. The activation of ET and Rho-kinase system may be crucial to negatively effect the clitoral smooth muscle relaxation in experimentally induced OAB animal model. But whether these vasomotor effects are revived in human clitoris is still debatable. Myung S-C, Lee M-Y, Lee S-Y, Yum S-H, Park S-H, and Kim S-C. Contractile changes of the clitoral cavernous smooth muscle in female rabbits with experimentally induced overactive bladder. J Sex Med 2008;5:1088,1096. [source] A study of airway management using the ProSeal LMA® laryngeal mask airway compared with the tracheal tube on postoperative analgesia requirements following gynaecological laparoscopic surgeryANAESTHESIA, Issue 9 2007M. Hohlrieder Summary In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMAÔ laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I,II, 18,75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery. [source] | ||||||||||||||||||||||||||||||||||