283 resultados para electromechanical response mechanisms
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Objective To study increases in electromyographic (EMG) response from the right and left rectus femoris muscles of individuals with long-term cervical spinal cord injuries after EMG biofeedback treatment. Design Repeated measure trials compared EMG responses before and after biofeedback treatment in patients with spinal cord injuries. Main outcome measures The Neuroeducator was used to analyse and provide feedback of the EMG signal and to measure EMG response. Setting Department of Traumatic Orthopaedics, School of Medicine, University of Sao Paulo, Brazil. Participants Twenty subjects (three men and 17 women), between 21 and 49 years of age, with incomplete spinal cord injury at level C6 or higher (range C2 to C6). Of these subjects, 10 received their spinal cord injuries from motor vehicle accidents, one from a gunshot, five from diving, three from falls and one from spinal disc herniation. Results Significant differences were found in the EMG response of the right rectus femoris muscle between pre-initial (T1), post-initial (T2) and additional (T3) biofeedback treatment with the subjects in a sitting position [mean (standard deviation) T1: 26 mu V (29); T2: 67 mu V (50); T3: 77 mu V (62)]. The mean differences and 95% confidence intervals for these comparisons were as follows: T1 to T2, -40.7 (-53.1 to -29.4); T2 to T3, -9.6 (-26.1 to 2.3). Similar differences were found for the left leg in a sitting position and for both legs in the sit-to-stand condition. Conclusions The EMG responses obtained in this study showed that treatment involving EMG biofeedback significantly increased voluntary EMG responses from right and left rectus femoris muscles in individuals with spinal cord injuries. (C) 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
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Study Design: Data mining of single nucleotide polymorphisms (SNPs) in gene pathways related to spinal cord injury (SCI). Objectives: To identify gene polymorphisms putatively implicated with neuronal damage evolution pathways, potentially useful to SCI study. Setting: Departments of Psychiatry and Orthopedics, Faculdade de Medicina, Universidade de Sao Paulo, Brazil. Methods: Genes involved with processes related to SCI, such as apoptosis, inflammatory response, axonogenesis, peripheral nervous system development and axon ensheathment, were determined by evaluating the `Biological Process` annotation of Gene Ontology (GO). Each gene of these pathways was mapped using MapViewer, and gene coordinates were used to identify their polymorphisms in the SNP database. As a proof of concept, the frequency of subset of SNPs, located in four genes (ALOX12, APOE, BDNF and NINJ1) was evaluated in the DNA of a group of 28 SCI patients and 38 individuals with no SC lesions. Results: We could identify a total of 95 276 SNPs in a set of 588 genes associated with the selected GO terms, including 3912 nucleotide alterations located in coding regions of genes. The five non-synonymous SNPs genotyped in our small group of patients, showed a significant frequency, reinforcing their potential use for the investigation of SCI evolution. Conclusion: Despite the importance of SNPs in many aspects of gene expression and protein activity, these gene alterations have not been explored in SCI research. Here we describe a set of potentially useful SNPs, some of which could underlie the genetic mechanisms involved in the post trauma spinal cord damage.
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Background This article provides a summary of the current status of the HIV/AIDS epidemic in Latin America, as well as an outline of the diverse responses to it. Methods A search of international databases (Pubmed and ISI-Web of Science), regional databases (Scielo and Lilacs), regional and national documents and UNAIDS reports. Data are presented according to subregion. Results In Mexico HIV remains concentrated among urban men who have sex with men (MSM), and has been growing among injecting drug users (IDU) and in rural areas in relation to migration. An increasing proportion of women among those affected is observed in all countries in Central America, the most affected region, as well as increasing the impact on other vulnerable groups, such as indigenous populations. The Andean Countries have urban epidemics concentrated among MSM. In Peru, non-traditional vulnerable populations were identified. In the Southern Cone heterosexual transmission became more relevant, probably in connection with IDU epidemics and is increasingly affecting lower income groups. Incidence rates have been declining since 2002 in Brazil, the first country to guarantee free, universal access to antiretrovirals, where one-third of drug-nave patients are still initiating treatment at an advanced stage. Generally, access to treatment has improved as a result of support from the Global Fund and other initiatives, but there are concerns regarding coverage, equity and sustainability. Conclusions HIV is still concentrated among MSM in Latin America. Non-traditional vulnerable groups such as migrants and lower income populations, usually considered part of the general population, deserve attention. Programmes confronting sexual exclusion are still needed. Access to treatment has improved over time, but inequalities persist.
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Pneumococcal vaccination has been recommended for immunocompromised children, including patients with chronic kidney disease. We determined pneumococcal immunoglobulin (Ig) G antibodies to serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F before and after 48 pediatric patients with chronic renal failure were administered heptavalent conjugated pneumococcal vaccine. The patients were between 1 and 9 years of age and were separated into a conservative treatment group (Group 1) and a dialysis group Group 2). The antibody response to the vaccinal serotypes was evaluated by measuring antibody concentrations before the first dose and 60 days after the second one. Pre-vaccinal IgG concentrations >= 0.35 mu g/ml were detected for all serotypes in at least 50% of the patients in both groups. Patients from both groups showed a statistically indistinguishable behavior in terms of the medians of post-vaccination IgG levels. An ""adequate"" vaccine response was defined as a post-immunization level of specific pneumococcal serotype antibody >= 0.35 mu g/ml, based on the World Health Organization`s (WHO) protective antibody concentration definition for pneumococcal conjugate vaccines, or on a fourfold increase over baseline for at least five of the seven antigens of the vaccine. An ""adequate"" vaccinal response was obtained in 100% of the patients of both groups using WHO`s definition, or in 45.8% of Group 1 patients and 37.5% of Group 2 patients when the criterion was a fourfold antibody increase over baseline antibody concentrations.
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TRAPS is the most common of the autosomal dominant periodic fever syndromes. It is caused by mutations in the TNFRSF1A gene, which encodes for the type 1 TNF-receptor (TNFR1). We describe here a Brazilian patient with TRAPS associated to a novel TNFRSF1A de novo mutation and the response to anti-TNF therapy. The patient is a 9-year-old girl with recurrent fevers since the age of 3 years, usually lasting 3 to 7 days, and recurring every other week. These episodes are associated with mild abdominal pain, nausea, vomiting and generalized myalgia. Recurrent conjunctivitis and erysipela-like skin lesions in the lower limbs also occur. Laboratory studies show persistent normocytic normochromic anemia, thrombocytosis, elevated erythrocyte sedimentation rate and C-reactive protein. IgD levels are normal. Mutational screening of TNFRSF1A revealed the association of a novel C30F mutation with the common R92Q low-penetrance mutation. The R92Q mutation is seen in 5% of the general population and is associated with an atypical inflammatory phenotype. The patient had a very good response to etanercept, with cessation of fever and normalization of inflammatory markers. Our report expands the spectrum of TNFRSF1A mutations associated with TRAPS, adding further evidence for possible additive effects of a low-penetration R92Q and cysteine residue mutations, and confirms etanercept as an efficacious treatment alternative.
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The Down syndrome (DS) immune phenotype is characterized by thymus hypotrophy, higher propensity to organ-specific autoimmune disorders, and higher susceptibility to infections, among other features. Considering that AIRE (autoimmune regulator) is located on 21q22.3, we analyzed protein and gene expression in surgically removed thymuses from 14 DS patients with congenital heart defects, who were compared with 42 age-matched controls with heart anomaly as an isolated malformation. Immunohistochemistry revealed 70.48 +/- 49.59 AIRE-positive cells/mm(2) in DS versus 154.70 +/- 61.16 AIRE-positive cells/mm(2) in controls (p < 0.0001), and quantitative PCR as well as DNA microarray data confirmed those results. The number of FOXP3-positive cells/mm(2) was equivalent in both groups. Thymus transcriptome analysis showed 407 genes significantly hypoexpressed in DS, most of which were related, according to network transcriptional analysis (FunNet), to cell division and to immunity. Immune response-related genes included those involved in 1) Ag processing and presentation (HLA-DQB1, HLA-DRB3, CD1A, CD1B, CD1C, ERAP) and 2) thymic T cell differentiation (IL2RG, RAG2, CD3D, CD3E, PRDX2, CDK6) and selection (SH2D1A, CD74). It is noteworthy that relevant AIRE-partner genes, such as TOP2A, LAMNB1, and NUP93, were found hypoexpressed in DNA microarrays and quantitative real-time PCR analyses. These findings on global thymic hypofunction in DS revealed molecular mechanisms underlying DS immune phenotype and strongly suggest that DS immune abnormalities are present since early development, rather than being a consequence of precocious aging, as widely hypothesized. Thus, DS should be considered as a non-monogenic primary immunodeficiency. The Journal of Immunology, 2011, 187: 3422-3430.
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Background: Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries. Method: We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory. Results: The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated. Conclusions: The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics. Copyright (C) 2010 John Wiley & Sons, Ltd.
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This case regards a 34-year-old woman with severe and refractory obsessive-compulsive disorder, who was enrolled in a double-blind, randomized controlled trial of radiosurgery. She was at first submitted to a sham radiosurgical procedure, and 1 year later to an active intervention. Opposite clinical responses were observed in the follow-up of these different phases. During the sham surgery follow-up, no improvements were observed, but a remarkable amelioration was seen a few months after the active procedure. Detailed descriptions of psychopathological changes and neuroimaging findings as well as a discussion regarding the surgical technique are provided. Copyright (C) 2010 S. Karger AG, Basel
Muscle sympathetic nervous activity in depressed patients before and after treatment with sertraline
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Background Sympathetic hyperactivity is one of the mechanisms involved in the increased cardiovascular risk associated with depression, and there is evidence that antidepressants decrease sympathetic activity. Objectives We tested the following two hypotheses: patients with major depressive disorder with high scores of depressive symptoms (HMDD) have augmented muscle sympathetic nervous system activity (MSNA) at rest and during mental stress compared with patients with major depressive disorder with low scores of depressive symptoms (LMDD) and controls; sertraline decreases MSNA in depressed patients. Methods Ten HMDD, nine LMDD and 11 body weight-matched controls were studied. MSNA was directly measured from the peroneal nerve using microneurography for 3 min at rest and 4 min during the Stroop color word test. For the LMDD and HMDD groups, the tests were repeated after treatment with sertraline (103.3 +/- 40 mg). Results Resting MSNA was significantly higher in the HMDD [29.1 bursts/min (SE 2.9)] compared with LMDD [19.9 (1.6)] and controls [22.2 (2.0)] groups (P=0.026 and 0.046, respectively). There was a significant positive correlation between resting MSNA and severity of depression. MSNA increased significantly and similarly during stress in all the studied groups. Sertraline significantly decreased resting MSNA in the LMDD group and MSNA during mental stress in LMDD and HMDD groups. Sertraline significantly decreased resting heart rate and heart rate response to mental stress in the HMDD group. Conclusion Moderate-to-severe depression is associated with increased MSNA. Sertraline treatment reduces MSNA at rest and during mental challenge in depressed patients, which may have prognostic implications in this group. J Hypertens 27:2429-2436 (c) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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Little is known about the effect of clinical characteristics, parental psychopathology, family functioning, and environmental stressors in the response to methylphenidate in children with attention-deficit/hyperactivity disorder (ADHD) followed up in a naturalistic setting. Data from cultures outside the United States are extremely scarce. This is a longitudinal study using a nonrandom assignment, quasi-experimental design. One hundred twenty-five children with ADHD were treated with methylphenidate according to standard clinical procedures, and followed up for 6 months. The severity of ADHD symptoms was assessed by the Swanson, Nolan, and Pelham rating scale. In the final multivariate model, ADHD combined subtype (P < 0.001) and comorbidity with oppositional defiant disorder (P = 0.03) were both predictors of a worse clinical response. In addition, the levels of maternal ADHD symptoms were also associated with worse prognosis (P < 0.001). In the context of several adverse psychosocial factors assessed, only undesired pregnancy was associated with poorer response to methylphenidate in the final comprehensive-model (P = 0.02). Our study provides evidence for the involvement of clinical characteristics, maternal psychopathology, and environmental stressors in the response to methylphenidate. Clinicians may consider adjuvant strategies when negative predictors are present to increase the chances of success with methylphenidate treatment.
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The persistent nature of addiction has been associated with activity-induced plasticity of neurons within the striatum and nucleus accumbens (NAc). To identify the molecular processes leading to these adaptations, we performed Cre/loxP-mediated genetic ablations of two key regulators of gene expression in response to activity, the Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) and its postulated main target, the cAMP-responsive element binding protein (CREB). We found that acute cocaine-induced gene expression in the striatum was largely unaffected by the loss of CaMKIV. On the behavioral level, mice lacking CaMKIV in dopaminoceptive neurons displayed increased sensitivity to cocaine as evidenced by augmented expression of locomotor sensitization and enhanced conditioned place preference and reinstatement after extinction. However, the loss of CREB in the forebrain had no effect on either of these behaviors, even though it robustly blunted acute cocaine-induced transcription. To test the relevance of these observations for addiction in humans, we performed an association study of CAMK4 and CREB promoter polymorphisms with cocaine addiction in a large sample of addicts. We found that a single nucleotide polymorphism in the CAMK4 promoter was significantly associated with cocaine addiction, whereas variations in the CREB promoter regions did not correlate with drug abuse. These findings reveal a critical role for CaMKIV in the development and persistence of cocaine-induced behaviors, through mechanisms dissociated from acute effects on gene expression and CREB-dependent transcription.
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Introduction: A variety of subjective experiences have been reported to be associated with the symptom expression of obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). First described in TS patients, these subjective experiences have been defined in different ways. There is no consensus in the literature on how to best define subjective experiences. This lack of consensus may hinder the understanding of study results and prevents the possibility of including them in the search for etiological factors associated with OCD and TS. Methods: The objective of this article was to review the descriptions of subjective experiences in the English-language literature from 1980-2007. This meta-analytic review was carried out using the English-language literature from 1980-2007 available on MEDLINE, PsycINFO, and the Cochrane Library databases using the following search terms: premonitory urges, sensory tics, ""just-right"" perceptions, sensory phenomena, sensory experiences, incompleteness, ""not just-right"" phenomena, obsessive-compulsive disorder and TS, including OCD and/or TS, in all combination searches. We also searched for the references cited in each article previously found that referred to the aforementioned terms. Thirty-one articles were included in the study. Results: Subjective experiences, in particular, the sensory phenomena, were important phenotypic variables in the characterization of the tic-related OCD subtype and were more frequent in the early-onset OCD subtype. There is a paucity of studies using structured interviews to assess sensory phenomena, their epidemiology and the etiological mechanisms associated with sensory phenomena. Conclusion: The current review provides some evidence that sensory phenomena can be useful to identify more homogenous subgroups of OCD and TS patients and should be included as important phenotypic variables in future clinical, genetic, neuroimaging, and treatment-response studies.
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Although venlafaxine is usually associated with modest increases in blood pressure and not so often clinical hypertension, there are a few reported cases of hypotension related to overdoses of this specific antidepressant. The case study of a young female patient with a history of Major Depressive Disorder who initiated treatment with venlafaxine 75 mg/day and developed hypotension when the dosage was titrated up to 225 mg/day is described. The patient did not present comorbid diseases nor use other medication. A temporal association and a dose-dependent relationship between the hypotension and the use of venlafaxine is shown. To the best of the knowledge of the authors, this is the first case report that specifically associates regular doses of venlafaxine with the presence of hypotension. A pathophysiological mechanism is proposed, involving the participation of presynaptic alpha2-adrenergic receptors and the presence of a possible genetic polymorphism of cytochrome P4502D6, which is associated with lower drug metabolization, to explain the relationship between venlafaxine in regular dosage and development of hypotension.
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Objective: Gorticosteroids have been proposed to be effective in modulating the inflammatory response and pulmonary tissue remodeling in acute lung injury (ALI). We hypothesized that steroid treatment might act differently in models of pulmonary (p) or extrapulmonary (exp) ALI with similar mechanical compromise. Design: Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects: One hundred twenty-eight BALB/c mice (20-25 g). Interventions: Mice were divided into six groups. In control animals sterile saline solution was intratracheally (0.05 mL, Cp) or intraperitoneally (0.5 mL, Gexp) injected, whereas ALI animals received Escherichia coli lipopolysaccharide intratracheally (10 mu g, ALIp) or intraperitoneally (125 mu g, ALIexp). Six hours after lipopolysaccharide administration, ALIp and ALlexp animals were further randomized into subgroups receiving saline (0.1 mL intravenously) or methylprednisolone (2 mg/kg intravenously, Mp and Mexp, respectively). Measurements and Main Results: At 24 hrs, lung state elastance, resistive and viscoelastic pressures, lung morphometry, and collagen fiber content were similar in both ALI groups. KC, interieukin-6, and transforming growth factor (TGF)-beta levels in bronchoatveolar lavage fluid, as well as tumor necrosis factor (TNF)-alpha, migration inhibitory factor (MIF), interferon (IFN)-gamma, TGF-beta 1 and TGF-beta 2 messenger RNA expression in lung tissue were higher in ALIp than in ALIexp animals. Methylprednisolone attenuated mechanical and morphometric changes, cytokine levels, and TNF-alpha, MIF, IFN gamma, and TGF-beta 2 messenger RNA expression only in ALIp animals, but prevented any changes in collagen fiber content in both ALI groups. Conclusions. Methylprednisolone is effective to inhibit fibrogenesis independent of the etiology of ALI, but its ability to attenuate inflammatory responses and lung mechanical changes varies according to the cause of ALI.
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Background: Androgenic anabolic steroids (AAS) are synthetic hormone derivatives of testosterone and are mainly used to enhance athletic performance and muscle mass, but medical applications also have been described. Short- and long-term side effects have been demonstrated in many organs, but the liver adverse effects are the most common and serious ones associated with AAS use. However, these effects have been supported by few clinical and experimental studies. Objective: To evaluate the hepatic function and structure after 5 wk of nandrolone decanoate administration at three different doses. Methods: Twenty-seven adult male Wistar rats were randomly assigned to the following groups: control, clinical, intermediate, and suprapharmacological doses of nandrolone decanoate during 5 wk. Results: The biochemical studies showed that nandrolone decanoate administration leads to a dose-dependent increase in serum levels of the aspartate aminotransferase (AST) (P < 0.05), alanine aminotransferase (ALT) (P < 0.01), and alkaline phosphatase (ALP) (P < 0.001), as well as a significant decrease in total proteins (P < 0.01), bilirubin (P < 0.05), total cholesterol and fractions (P < 0.05), and triglycerides (P < 0.05). Although a significant statistical difference was found for AST, ALT, and ALP when compared with the control group, their values remained within the normal range. The number of Kupffer cells was increased in the liver parenchyma (P < 0.05), and the content of collagen was increased in the central lobular vein wall, in the hepatic parenchyma, and in the portal space (P < 0.05). Conclusions: These results suggest that subchronic treatment with nandrolone decanoate, mainly administered at higher-than-clinical doses, are potentially deleterious to the liver, leading to incipient fibrosis.