Norepinephrine remains increased in the six-minute walking test after heart transplantation

Sympathetic Reinnervation of Intact and Upper Follicle Xenografts into BALB/c-nu/nu Mice

Increasing concerns about hair loss affect people's quality of life. Recent studies have found that sympathetic nerves play a positive role in regulating hair follicle stem cell activity to promote hair growth. However, no study has investigated sympathetic innervation of transplanted follicles. Rat vibrissa follicles were extracted and implanted under the dorsal skin of BALB/c-nu/nu mice using one of two types of follicles: (1) intact follicles, where transplants included bulbs, and (2) upper follicles, where transplants excluded bulbs. Follicular samples were collected for hematoxylin and eosin staining, immunofluorescence staining for tyrosine hydroxylase (TH, a sympathetic marker) and enzyme-linked immunosorbent assays. At 37 days after implantation in both groups, follicles had entered anagen, with the growth of long hair shafts; tyrosine-hydroxylase-positive nerves were innervating follicles (1.45-fold); and norepinephrine concentrations (2.03-fold) were significantly increased compared to 5 days, but did not return to normal. We demonstrate the survival of intact and upper follicle xenografts and the partial restoration of sympathetic reinnervations of both transplanted follicles.

Relationships among norepinephrine levels, exercise capacity, and chronotropic responses in heart failure patients

In heart failure (HF) patients, the pathophysiological mechanisms of severe exercise intolerance and impaired exercise capacity are related to both central and peripheral abnormalities. The central abnormalities in HF patients include impaired cardiac function and chronotropic incompetence (CI). Indeed, CI, the inability to adequately increase heart rate (HR) from rest to exercise often exhibited by HF patients, is related to activation of the sympathetic nervous system (SNS) yielding a rise in circulating norepinephrine (NE). CI may result from downregulation of β-adrenergic receptors, β-blocker usage, high baseline HR, or due to a combination of factors. This paper discusses the role of elevated NE in altering chronotropic responses in HF patients and consequently resulting in impaired exercise capacity. We suggest that future research should focus on the potential treatment of CI with rate-adaptive pacing, using a sensor to measure physical activity, without inducing deleterious hormonal activation of the sympathetic system.

Cardiac reinnervation affects cardiorespiratory adaptations to exercise training in individuals with heart transplantation

PURPOSE

The purpose of this study was to investigate the hemodynamic and cardiorespiratory adaptations to exercise in individuals with heart transplantation with evidence of cardiac reinnervation (cardiac reinnervation group) versus without evidence of cardiac reinnervation (no cardiac reinnervation group).

METHODS

Sedentary individuals with heart transplantation (age = 45.5 ± 2.2 years; time elapsed since surgery = 6.7 ± 0.7 years) were divided into the cardiac reinnervation (n = 16) and no cardiac reinnervation (n = 17) groups according to their heart rate response to cardiopulmonary exercise testing. The 24-hour ambulatory blood pressure, carotid-femoral pulse wave velocity, and cardiorespiratory fitness were assessed before and after 12 weeks of a thrice-weekly exercise program (five minutes of warm-up, 30 min of endurance exercise, one set of 10-15 reps in five resistance exercises, and five minutes of cool-down).

RESULTS

The cardiac reinnervation group had reduced (p < 0.01) 24-hour systolic/diastolic blood pressure (7/9 mm Hg), daytime systolic/diastolic blood pressure (9/10 mm Hg) and nighttime diastolic blood pressure (6 mm Hg) after training. The no cardiac reinnervation group reduced (p < 0.05) only 24-hour (5 mm Hg), daytime (5 mm Hg) and nighttime (6 mm Hg) diastolic blood pressure after training. Hourly analysis showed that the cardiac reinnervation group reduced systolic/diastolic blood pressure for 10/21 h, while the no cardiac reinnervation group reduced systolic/diastolic blood pressure for only 3/11 h. The cardiac reinnervation group also improved both maximal oxygen consumption (10.8%) and exercise tolerance (13.4%) after training, but the no cardiac reinnervation group improved only exercise tolerance (9.9%). Pulse wave velocity did not change in both groups.

CONCLUSION

There were greater improvements in ambulatory blood pressure and maximal oxygen consumption in the cardiac reinnervation than the no cardiac reinnervation group. These results suggest that cardiac reinnervation associates with hemodynamic and cardiorespiratory adaptations to exercise training in individuals with heart transplantation.

Effect of a physical therapy protocol on the health related quality of life of patients with temporomandibular disorder

Abstract Introduction: Temporomandibular disorders (TMD) comprise a group of diseases that affect not only the temporomandibular joint, but also different areas extrinsic to the joints. Quality of life has been the subject of numerous studies in the Health area, especially aimed at people with chronic diseases, such as TMD. Objective: To evaluate effects of a physical therapy protocol on the quality of life of patients with temporomandibular disorder. Methods: Blinded, prospective, clinical trial, with 60 patients of both genders, aged between 18 and 70 years with TMD diagnosis attended in the clinic of Ribeirão Preto School of Dentistry. The patients were divided into two groups, with one group, in addition to dental treatment, receiving a physical therapy protocol and the other group dental treatment only, for 5 weeks. The measurement of quality of life was obtained through the generic SF-36 questionnaire, at the beginning and end of the proposed protocol. Results: The patients to whom the physical therapy protocol was applied associated with dental care presented increased scores in all the domains of the questionnaire. In the group that received only dental treatment, improvements were only found in the domain related to pain. Conclusion: The application of a physical therapy protocol was able to improve the quality of life of patients with temporomandibular disorder.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients

BACKGROUND

Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients.

METHODS

40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX).

RESULTS

The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p < 0.01) and daytime (4.8 ± 1.6 mm Hg, p < 0.01) systolic ABP, and 24-hour (7.0 ± 1.4 mm Hg, p < 0.001) daytime (7.5 ± 1.6 mm Hg, p < 0.001) and nighttime (5.9 ± 1.5 mm Hg, p < 0.001) diastolic ABP after the intervention. The ET group also had improved Vo2MAX (9.7% ± 2.6%, p < 0.001) after the intervention. However, PWV did not change after ET. No variable was changed in the control group after the intervention.

CONCLUSIONS

The 12-week ET program was effective for reducing ABP but not PWV in heart transplant recipients. This result suggests that endurance ET may be a tool to counteract hypertension in this high-risk population.

Exercise and its interactions with various aspects of man and animal lives

To review recently published papers in the Brazilian Scientific press on the general subject of physical exercise. All articles published in 2010/2011 found through the keyword exercise were collected from 11 Brazilian Journals. They were hand filtered to exclude all but original research papers. They were grouped according to subject categories and subcategories. A brief summary of all included articles was produced, comparing similar articles between them. The most commonly found interactions refer to exercise vs. the cardiovascular system, metabolism and the locomotor system, in this order. The volume of scientific research in the field is high and of sufficient quality to justify highlighting.

Prognostic value of the six-minute walk test in end-stage renal disease life expectancy: a prospective cohort study

OBJECTIVES

The six-minute walk test has been widely used to evaluate functional capacity and predict mortality in several populations. Thus, the aim of this study was to evaluate the prognostic value of the six-minute walk test for the life expectancy of end-stage renal disease patients.

METHODS

Patients over 18 years old who underwent hemodialysis for at least six months were included. Patients with hemodynamic instability, smoking, chronic obstructive pulmonary disease, physical incapacity and acute myocardial stroke in the preceding three months were excluded.

RESULTS

Fifty-two patients (54% males; 36+11 years old) were followed for 144 months. The distance walked in the six-minute walk test was a survival predictor for end-stage renal disease patients. In the multivariate analysis, for each 100 meters walked with a 100-meter increment, the hazard ratio was 0.53, with a 95% confidence interval of 0.37-0.74. There was a positive correlation between the distance walked in the six-minute walk test and peak oxygen consumption (r = 0.508). In the multivariate analysis, each year of dialysis treatment represented a 10% increase in death probability; in the severity index analysis, each point on the scale represented an 11% increase in the death risk.

CONCLUSIONS

We observed that survival increased approximately 5% for every 100 meters walked in the six-minute walk test, demonstrating that the test is a viable option for evaluating the functional capacity in patients with end-stage renal disease.

Predictors of low cardiac output in decompensated severe heart failure

OBJECTIVE

To identify predictors of low cardiac output and mortality in decompensated heart failure.

INTRODUCTION

Introduction: Patients with decompensated heart failure have a high mortality rate, especially those patients with low cardiac output. However, this clinical presentation is uncommon, and its management is controversial.

METHODS

We studied a cohort of 452 patients hospitalized with decompensated heart failure with an ejection fraction of <0.45. Patients underwent clinical-hemodynamic assessment and Chagas disease immunoenzymatic assay. Low cardiac output was defined according to L and C clinical-hemodynamic profiles. Multivariate analyses assessed clinical outcomes. P<0.05 was considered significant.

RESULTS

The mean age was 60.1 years; 245 (54.2%) patients were >60 years, and 64.6% were men. Low cardiac output was present in 281 (63%) patients on admission. Chagas disease was the cause of heart failure in 92 (20.4%) patients who had higher B type natriuretic peptide levels (1,978.38 vs. 1,697.64 pg/mL; P = 0.015). Predictors of low cardiac output were Chagas disease (RR: 3.655, P<0.001), lower ejection fraction (RR: 2.414, P<0.001), hyponatremia (RR: 1.618, P = 0.036), and renal dysfunction (RR: 1.916, P = 0.007). Elderly patients were inversely associated with low cardiac output (RR: 0.436, P = 0.001). Predictors of mortality were Chagas disease (RR: 2.286, P<0.001), ischemic etiology (RR: 1.449, P = 0.035), and low cardiac output (RR: 1.419, P = 0.047).

CONCLUSIONS

In severe decompensated heart failure, predictors of low cardiac output are Chagas disease, lower ejection fraction, hyponatremia, and renal dysfunction. Additionally, Chagas disease patients have higher B type natriuretic peptide levels and a worse prognosis independent of lower ejection fraction.