286 resultados para Muscle Function
Resumo:
Background: The progression of heart failure in Chagas` disease has been explained by remodeling, leading to neurohumoral activation, or by the direct parasite damage to parasympathetic neurons during acute phase, leading to early sympathetic activation and progressive heart failure. To help distinguish between these hypotheses we studied muscle sympathetic nerve activity (MSNA) at rest and during handgrip exercise (30% of maximal voluntary contraction) in patients with Chagas` disease and normal ejection fraction vs. patients with heart failure. Methods: A consecutive study of 72 eligible out-patients/subjects was conducted between July 1998 and November 2004. The participants were classified in three advanced heart failure groups (New York Heart Association Functional Classes II-III): Chagas` disease (n-15), ischemic (n=15) and idiopathic cardiomyopathy (n-15). Twelve Chagas` disease patients without heart failure and normal ejection fraction, and 15 normal controls were also studied. MSNA was recorded directly from the peroneal nerve by microneurography technique. Results: MSNA was greater in heart failure patients when compared with Chagas` disease patients without heart failure (51 +/- 3 vs. 20 +/- 2 bursts/min P=0.0001). MSNA in Chagas` patients with normal ejection fraction and normal controls was not different. During exercise, MSNA was similar in all 3 heart failure groups. And, was lower in the Chagas` patients with normal ejection fraction than in patients with Chagas` disease and heart failure (28 +/- 1 vs. 63 +/- 5 bursts/min, respectively). Conclusion: MSNA is not elevated in patients with Chagas` disease with normal ejection fraction. These findings support the concept of remodeling and neurohumoral activation as a common pathway following significant cardiac injury. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Background: Previous studies have associated neurohumoral excitation, as estimated by plasma norepinephrine levels, with increased mortality in heart failure. However, the prognostic value of neurovascular interplay in heart failure (HF) is unknown. We tested the hypothesis that the muscle sympathetic nerve activity (MSNA) and forearm blood flow would predict mortality in chronic heart failure patients. Methods: One hundred and twenty two heart failure patients, NYHA II-IV, age 50 +/- 1 ys, LVEF 33 +/- 1%, and LVDD 7.1 +/- 0.2 mm, were followed up for one year. MSNA was directly measured from the peroneal nerve by microneurography. Forearm blood flow was obtained by venous occlusion plethysmography. The variables were analyzed by using univariate, stepwise multivariate Cox proportional hazards analysis, and Kaplan-Meier analysis. Results: After one year, 34 pts died from cardiac death. The univariate analysis showed that MSNA, forearm blood flow, LVDD, LVEF, and heart rate were significant predictors of mortality. The multivariate analysis showed that only MSNA (P = 0.001) and forearm blood flow (P = 0.003) were significant independent predictors of mortality. On the basis of median levels of MSNA, survival rate was significantly lower in pts with >49 bursts/min. Similarly, survival rate was significantly lower in pts with forearm blood flow <1.87 ml/min/100 ml (P = 0.002). Conclusion: MSNA and forearm blood flow predict mortality rate in patients with heart failure. It remains unknown whether therapies that specifically target these abnormalities will improve survival in heart failure. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Study Objectives: To test the effects of exercise training on sleep and neurovascular control in patients with systolic heart failure with and without sleep disordered breathing. Design: Prospective interventional study. Setting: Cardiac rehabilitation and exercise physiology unit and sleep laboratory. Patients: Twenty-five patients with heart failure, aged 42 to 70 years, and New York Heart Association Functional Class I-III were divided into 1 of 3 groups: obstructive sleep apnea (n = 8), central sleep apnea (n 9) and no sleep apnea (n = 7). Interventions: Four months of no-training (control) followed by 4 months of an exercise training program (three 60-minute, supervised, exercise sessions per week). Measures and Results: Sleep (polysomnography), microneurography, forearm blood flow (plethysmography), peak VO(2). and quality of life were evaluated at baseline and at the end of the control and trained periods. No significant changes occurred in the control period. Exercise training reduced muscle sympathetic nerve activity (P < 0.001) and increased forearm blood flow (P < 0.01), peak VO(2) (P < 0.01), and quality of life (P < 0.01) in all groups, independent of the presence of sleep apnea. Exercise training improved the apnea-hypopnea index, minimum O(2) saturation, and amount stage 3-4 sleep (P < 0.05) in patients with obstructive sleep apnea but had no significant effects in patients with central sleep apnea. Conclusions. The beneficial effects of exercise training on neurovascular function, functional capacity, and quality of life in patients with systolic dysfunction and heart failure occurs independently of sleep disordered breathing. Exercise training lessens the severity of obstructive sleep apnea but does not affect central sleep apnea in patients with heart failure and sleep disordered breathing.
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Extreme myocardial degeneration leading to advanced stages of cardiomyopathy with extensive atrophy is rarely observed before patients die. However, heterotopic transplantation is a special situation wherein this phenomenon can be observed. The greater part of the failed heart shows recuperation after receiving circulatory assistance by reduction of myocardial work. Herein we have reported an unusual behavior of degenerative cardiomyopathy associated with intense myocardial apoptosis resulting in extreme ventricular atrophy after heterotopic heart transplantation. An 11-year-old girl with end-stage heart failure due to dilated cardiomyopathy of undetermined etiology without pulmonary hypertension underwent heterotopic cardiac transplantation with an undersized (by weight mismatch) donor heart. After 9 years heart failure reappeared due to native heart enlargement leading to allograft compression. The patient underwent native heart replacement leaving her with 2 donor hearts. Despite normal hemodynamic recuperation, the patient experienced massive arterial microemboli which led to death. Pathological studies showed exuberant myocardial degeneration in the native heart with intense atrophy of the muscle and gigantic ventricular enlargement. The left ventricle wall was extremely thin with rarefaction of cardiomyocytes and replacement by fibrosis. The right ventricle showed old extensive thrombosis. In conclusion, this report is not usual as it is not frequent to observe cardiomyopathy with an intense degree of myocardial degeneration and atrophy, because the patient dies earlier. In special situations it is possible that a recipient may have 2 donor hearts with normal hemodynamics. Heterotopic heart transplantation is a surgical alternative in a priority situation offering excellent outcomes; however, the native heart must be removed when there is compromise of the function of the heterotopic allograft.
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Background - The effect of prearrest left ventricular ejection fraction ( LVEF) on outcome after cardiac arrest is unknown. Methods and Results - During a 26-month period, Utstein-style data were prospectively collected on 800 consecutive inpatient adult index cardiac arrests in an observational, single-center study at a tertiary cardiac care hospital. Prearrest echocardiograms were performed on 613 patients ( 77%) at 11 +/- 14 days before the cardiac arrest. Outcomes among patients with normal or nearly normal prearrest LVEF ( >= 45%) were compared with those of patients with moderate or severe dysfunction ( LVEF < 45%) by chi(2) and logistic regression analyses. Survival to discharge was 19% in patients with normal or nearly normal LVEF compared with 8% in those with moderate or severe dysfunction ( adjusted odds ratio, 4.8; 95% confidence interval, 2.3 to 9.9; P < 0.001) but did not differ with regard to sustained return of spontaneous circulation ( 59% versus 56%; P = 0.468) or 24-hour survival ( 39% versus 36%; P = 0.550). Postarrest echocardiograms were performed on 84 patients within 72 hours after the index cardiac arrest; the LVEF decreased 25% in those with normal or nearly normal prearrest LVEF ( 60 +/- 9% to 45 +/- 14%; P < 0.001) and decreased 26% in those with moderate or severe dysfunction ( 31 +/- 7% to 23 +/- 6%, P < 0.001). For all patients, prearrest beta-blocker treatment was associated with higher survival to discharge ( 33% versus 8%; adjusted odds ratio, 3.9; 95% confidence interval, 1.8 to 8.2; P < 0.001). Conclusions - Moderate and severe prearrest left ventricular systolic dysfunction was associated with substantially lower rates of survival to hospital discharge compared with normal or nearly normal function.
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Our aim was to analyze the influence of subtle cochlear damage on temporal auditory resolution in tinnitus patients. Forty-eight subjects (hearing threshold <= 25 dB HL) were assigned to one of two experimental groups: 28 without auditory complaints (mean age, 28.8 years) and 20 with tinnitus (mean age, 33.5 years). We analyzed distortion product otoacoustic emission growth functions (by threshold, slope, and estimated amplitude), extended high-frequency thresholds, and the Gaps-in-Noise test. There were differences between the groups, principally in the extended high-frequency thresholds and the Gaps-in-Noise test results. Our findings suggest that subtle peripheral hearing impairment affects temporal resolution in tinnitus, even when pure-tone thresholds as conventionally measured appear normal. Copyright (C) 2010 S. Karger AG, Basel
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Tetanus still remains a significant health problem in developing countries; it is a serious disease with a high mortality rate. The purpose of this study was to characterize the oral sensorimotor function for feeding in patients with tetanus. Thirteen patients clinically diagnosed with tetanus and admitted to an intensive care unit between December of 2005 and May of 2007 underwent a screening too) for dysphagia, involving the assessment of clinical features and 2 swallowing tests. Results indicate that the oral sensorimotor function for feeding in these patients is severely compromised, with the exception for the clinical feature of palate elevation and performance in the saliva swallowing test. The factor analysis indicated that the evaluation of tongue movement change in the oromotor examination is important in predicting alterations of cough/voice in the water swallowing test, thus suggesting that oral feeding might be unsafe. When looking at developing countries, the prolonged intensive medical and nursing care required by many patients with tetanus places extra demands on an already stretched healthcare budget. Intervention by a speech pathologist could mean that time in the ICU would be reduced as well as the number of re-admissions due to complications. (C) 2009 Elsevier B.V. All rights reserved.
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Matrix metalloproteinases (MMPs) are crucial to the development and maintenance of healthy tissue and are mainly involved in extracellular matrix (ECM) remodeling of skeletal muscle. This study evaluated the effects of chronic allergic airway inflammation (CAAI), induced by ovalbumin, and aerobic training in the MMPs activity in mouse diaphragm muscle. Thirty mice were divided into 6 groups: 1) control; 2) ovalbumin; 3) treadmill trained at 50% of maximum speed; 4) ovalbumin and trained at 50%; 5) trained at 75%; 6) ovalbumin and trained at 75%. CAAI did not after MMPs activities in diaphragm muscle. Nevertheless, both treadmill aerobic trainings, associated with CAAI increased the MMP-2 and -1 activities. Furthermore, MMP-9 was not detected in any group. Together, these findings suggest an ECM remodeling in diaphragm muscle of asthmatic mice submitted to physical training. This result may be useful for a better understanding of functional significance of changes in the MMPs activity in response to physical training in asthma.
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Obesity can negatively affect pulmonary function tests, with or without clinical symptoms, but the impact of bariatric weight loss is still debated. Aiming to document such profile in a consecutive homogeneous population, a prospective cohort study was undertaken. Sixty-one patients (100% females, age 40 +/- 8 years, BMI 49 +/- 5 kg/m(2) and without respiratory disease) were enrolled. Spirometric analysis was carried out to compare preoperative respiratory pattern with outcome after 6 and 12 months. Variables included vital capacity (VC), expiratory reserve volume (ERV), forced expiratory volume (1 s) (FEV1), FEV1/FVC ratio and maximum voluntary ventilation (MVV). Correlation of results with weight loss was examined. The following initial variables exhibited significant difference when compared to the 12-month postoperative control: FVC (P = 0.0308), FEV1/FVC (P = 0.1998), MVV (P = 0.0004) and ERV (P = 0.2124). Recovery of FVC and FEV1/FVC occurred earlier by 6 months. The most seriously depressed preoperative finding was ERV, which even after 1 year still remained inadequate. (1) Pulmonary limitations were diagnosed in approximately one third of the population. (2) Changes were demonstrated for FVC, FEV1/FVC, ERV and MVV. (3) FEV1 and FEV1/FVC were acceptable due to the absence of an obstructive pattern. (4) Two variables increased by 6 months (FEV1/FVC and ERV), whereas recovery for others was confirmed after 1 year. (5) The only exception was ERV which continued below the acceptable range.
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We examined the association between IL28B single-nucleotide polymorphism rs12979860, hepatitis C virus (HCV) kinetic, and pegylated interferon alpha-2a pharmacodynamic parameters in HIV/HCV-coinfected patients from South America. Twenty-six subjects received pegylated interferon alpha-2a + ribavirin. Serum HCV-RNA and interferon concentrations were measured frequently during the first 12 weeks of therapy and analyzed using mathematical models. African Americans and whites had a similar distribution of IL28B genotypes (P = 0.5). The IL28B CC genotype was overrepresented (P = 0.015) in patients infected with HCV genotype-3 compared with genotype-1. In both genotype-1 and genotype-3, the first-phase viral decline and the average pegylated interferon-alpha-2a effectiveness during the first week of therapy were larger (trend P <= 0.12) in genotype-CC compared with genotypes-TC/TT. In genotype-1 patients, the second slower phase of viral decline (days 2-29) and infected cells loss rate, delta, were larger (P = 0.02 and 0.11, respectively) in genotype-CC than in genotypes-TC/TT. These associations were not observed in genotype-3 patients.
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Background. Previous works showed potentially beneficial effects of a single session of peripheral nerve sensory stimulation (PSS) on motor function of a paretic hand in patients with subacute and chronic stroke. Objective. To investigate the influence of the use of different stimulus intensities over multiple sessions (repetitive PSS [RPSS]) paired with motor training. Methods. To address this question, 22 patients were randomized within the second month after a single hemispheric stroke in a parallel design to application of 2-hour RPSS at 1 of 2 stimulus intensities immediately preceding motor training, 3 times a week, for 1 month. Jebsen-Taylor test (JTT, primary endpoint measure), pinch force, Functional Independence Measure (FIM), and corticomotor excitability to transcranial magnetic stimulation were measured before and after the end of the treatment month. JTT, FIM scores, and pinch force were reevaluated 2 to 3 months after the end of the treatment. Results. Baseline motor function tests were comparable across the 2 RPSS intensity groups. JTT improved significantly in the lower intensity RPSS group but not in the higher intensity RPSS group at month 1. This difference between the 2 groups reduced by months 2 to 3. Conclusions. These results indicate that multiple sessions of RPSS could facilitate training effects on motor function after subacute stroke depending on the intensity of stimulation. It is proposed that careful dose-response studies are needed to optimize parameters of RPSS stimulation before designing costly, larger, double-blind, multicenter clinical trials.
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Objective To assess MHC I and II expressions in muscle fibres of juvenile dermatomyositis (JDM) and compare with the expression in polymyositis (PM), dermatomyositis (DM) and dystrophy. Patients and methods Forty-eight JDM patients and 17 controls (8 PM, 5 DM and 4 dystrophy) were studied. The mean age at disease onset was 7.1 +/- 3.0 years and the mean duration of weakness before biopsy was 9.4 +/- 12.9 months. Routine histochemistry and immunohistochemistry (StreptABComplex/HRP) for MHC I and II (Dakopatts) were performed on serial frozen muscle sections in all patients. Mann-Whitney, Kruskal Wallis, chi-square and Fisher`s exact statistical methods were used. Results MHC I expression was positive in 47 (97.9%) JDM cases. This expression was observed independent of time of disease corticotherapy previous to muscle biopsy and to the grading of inflammation observed in clinical, laboratorial and histological parameters. The expression of MHC I was similar on JDM, PM and DM, and lower in dystrophy. On the other hand, MHC II expression was positive in just 28.2% of JDM cases was correlated to histological features as inflammatory infiltrate, increased connective tissue and VAS for global degree of abnormality (p < 0.05). MCH II expression was similar in DM/PM and lower in JDM and dystrophy, and it was based on the frequency of positive staining rather than to the degree of the MCH II expression. Conclusions MHC I expression in muscle fibres is a premature and late marker of JDM patient independent to corticotherapy, and MHC II expression was lower in JDM than in PM and DM.
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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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Background: Endoscopic sclerotherapy (ES) has been the standard treatment for children with idiopathic extrahepatic portal vein obstruction (EHPVO). Portosystemic shunts are indicated when variceal bleeding cannot be controlled by ES. Recently, mesenteric left portal vein bypass was indicated as a surgical intervention and preventative measure for hepatic dysfunction in children with long-term EHPVO. Nevertheless, there is a lack Of published data confirming the extent of hepatic dysfunction, hypersplenism, and physical development in children with long-term follow-up. Method: We retrospectively verified the long-term outcomes in 82 children with EHPVO treated with ES protocol, focusing on mortality, control of bleeding, hypersplenism, and consequent hepatic dysfunction. Results: Of the children, 56% were free from bleeding after the initiation of ES. The most frequent cause of rebleeding was gastric varices (30%). Four patients had recurrent bleeding from esophageal varices (4.6%). Four patients underwent surgery as a consequence of uncontrolled gastric varices. There were no deaths. Most patients showed good physical development. We observed a mild but statistically significant drop in factor V motion, as well as leukocyte and platelet count. Conclusion: Endoscopic sclerotherapy is an efficient treatment for children with EHPVO. The incidence of rebleeding is low, and there was no mortality. Children develop mild liver dysfunction and hypersplenism with long-term follow-up. Only a few patients manifest symptoms of hypersplenism, portal biliopathy, or liver dysfunction before adolescence. (C) 2009 Elsevier Inc. All rights reserved.
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The objective of this study is to evaluate the entries associated to the sexual function of patients undergoing physical disability rehabilitation, as well as the course of changes and medical approach through a retrospective review of medical charts. Methods: Medical records referring to the period between July and September, 1998 were evaluated. The data was divided into two groups, records containing physician`s entries on sexual function and/or entries of other health care professionals. The following aspects were investigated: whether complaints were spontaneously voiced by the patient, and whether diagnosis had been reached, with corresponding management. Results: Out of 245 medical records investigated, 17 (6.9%) contained clinical observations on the sexual function; out of those, 14 reached diagnosis. Twelve records (4.9%) had information by non-medical healthcare professionals. Out of 17 entries by doctors, 16 referred to male patients, which was found to be significant (p = 0.0202). Conclusions: Records for the sexual function of patients undergoing physical rehabilitation are scarce. In this population, the sexual function of male patients had more extensive investigation on the part of physicians when compared to other health care professionals.