Childhood obesity and its cardiovascular implications: a current view

Abstract Obesity is a universal disease of increasing prevalence and currently assumes epidemiological characteristic, as a main public health issue in contemporary society. Results from genetic, behavioral and environmental factors and it may start at any age. However, obesity appears at early ages predisposes to its presence at later ages bringing several complications, particularly the development of cardiovascular disease. The analysis indicates that autonomic dysfunction seems to be presented among the majority of risk factors that develop this disease, suggesting the need for a deeper study of this mechanism in children population.(AU)

Production of knowledge on myocardial, exercise andmenopause. Analysis of methodological approaches

Considering the importance of histological studies for the analysis of myocardial cell morphology and theeffects produced by this muscle exercise in postmenopausal women, a literature review was carried out toanalyze selected articles in PubMed, Medline, SciELO and Science Direct. 2001-2011 databases and to identifythe study design relating to morphological infarction, exercise and menopause published over the last 10 years.Materials and Methods:After the selection according to the proposed inclusion criteria, the journals andarticles were analyzed regarding the title, year of publication, country of origin, type of methodology, type ofauthorship and research subjects.Results:We foundthirty-four articles related to myocardium, menopauseand exercise from 2001-2011. In two of them the myocardium morphologically was evaluated, and in one ofthem there was a morphological and stereological cardiac muscle analysis.Conclusion: The main characteristicsof the publications are: multiple authorship, publications in journals from different areas, literature review andexperimental study as methodology, and all studies showed quantitative data analysis.

What is the most effective protocol to induce fatiguein knee joint muscles? a systematic review

The aim of this study was to review the literature to see how the protocols are designed to induce kneejoint muscles fatigue using an isokinetic dynamometer. Materials and Methods: This study consisted of asystematic review and the search for the theoretical composition was performed in the PubMed databaseusing as descriptors the words muscle fatigue, knee, and isokinetic, and as filters the words Abstract available,Humans, Randomized Controlled Trial, and English language. It was not set limits for year of publications.Results: twenty nine studies were found, from which, seventeen were excluded due to exclusion criteria.Conclusion: It became evident in the present review that the greatest reduction in the peak torque occurs inprotocols that use series of trials without determining the number of repetitions, requiring that the movementbe executed until attaining exhaustion. However, if there is a need to determine a number of repetitionsto decrease the the knee joint torque to the levels close to the one attained in the exhaustion protocol, theprotocol that most reduced the knee joint flexor and extensor torque was the one that used five series of 30repetitions with interval of one minute between series, independent of the angular speed and the type ofcontraction, concentric or excentric.

Effects of resistance exercise on ascendent aorta on ovariectomized elderly rats

Studies have shown a strong relationship between menopause, diet, physical inactivity and presence of risk factors causing endothelial and tissue damages, leading to increased risk of developing cardiovascular disease. The aim of this study was to investigate the influence of resistance training on the effects of estrogen deprivation in aortic collagen and elastic tissue in aging. Fifteen Wistar female rats, 4 months-old, average weight 240 g were studied. All animals were ovariectomized at 6 months of age, after divided into 3 groups (n = 5): Sedentary adult (13 months), Sedentary old and Trained old (both with 17 months). All animals were ovariectomized at 6 months of age. The animals were observed for 8 months after its ovariectomy and then submitted to resistance training protocol during 12 weeks. At the end of the experiment the animals were euthanized. Samples of the ascending aorta were sectioned, fixed, processed and stained for examination by light microscopy. Photomicrographs were used for stereological study and analyzed the following parameters: body weight, volume density of collagen fibers and elastic lamellae. No significant difference was found between the initial and final weights in the studied groups. Resistance training attenuates the increase in volume density of elastic lamellae (21%) and collagen fibers (16%), when compared with the sedentary older group.

Influence of resistance training in left ventricle of ovariectomized elderly rats

Several cardiovascular changes evoked by aging affect negatively the quality of people’s lives, among them is the reduced functional capacity. Menopausal women, affected by the suspension of the ovarian hormones, suffer more intensely from metabolic and cardiovascular changes. It is known that physical training causesbiochemical, electrical, morphological, and mechanical adaptations in the cardiac muscle, which togetherprovide an improvement in the cardiac function. The goal of the present study was to evaluate theeffect of resistance training in the left ventricle of ovariectomized rats through stereological analysis. Westudied  15  Wistar female rats, 4 months- old, average weight 240 g. All animals were ovariectomized at9 months of age and then divided into 3 groups of five individuals as follows: Ovariectomized Sedentary Adult(13 months) (OSA), Ovariectomized Sedentary Elderly (17 months) (OSE), and Ovariectomized TrainedElderly (17 months) (OTE). The rats were monitored for 13 months and subsequently underwent resistancetraining for 12 weeks. The stereological analysis was performed using light microscopy techniques and dataobtained for each group were tabulated and statistically compared using ANOVA and post hoc Tukey tests(p ≤ 0.05). It was verified that training decreased volume density of myocyte, interstitium and collagen fibersfollowed by increased volume density of capillaries, when compared with the ovariectomized sedentary elderly(OSE). Our data suggest that resistance training minimizes changes in the myocardium of elderly rats deprivedof ovarian hormones.

Resistance training and androgenic anabolic steroids on aged skeletal muscles: a review about methodological approaches

One of the most frequent effects of aging is the involuntary loss of muscle mass, strength and function, termed sarcopenia. Longitudinal data suggest that muscle strength is a robust predictor of functional decline that occur during aging. Since strength capacity appears to also be indicative of disability, resistance training may serve as an effective mode of physical activity to directly improve functional capacity. There is also a growing evidence to indicate that age-related decline in production and activity of hormones plays an important role in aging muscle. Testosterone deficiency has been associated with a marked decrease in measures of whole body protein anabolism and decrease strength. The purpose of the present study was to explore the characteristics of the methodological approaches used in the studies related to the role of resistance training and androgenic anabolic steroids in the aged skeletal muscle that have been published in the last ten years. A literature review was conducted in April 2011 using the following databases: PubMed; Medline; Lilacs; and Scielo. We found sixty two articles analyzing the influence of resistance training on skeletal muscle of aged samples, seven articles which proposed to verify the chronic influence of androgenic anabolic steroids and only one article mixing both interventions. The great variety of analysis methods is notable. Morphological analysis was done in only few articles.

Effects of estrogen deprivation and physical exerciseson the arterial wall: a literature review

Over the past few decades, there has been a surge of interest in the study of the effect of estrogen on the femaleorganism and the benefits of physical activities on different species of animals. The literature review provides areview of the existing literature on the morphological and/or physiological effects of the estrogen deprivationand/or the role of physical exercises on the arteries of different species of animals and humans. This reviewincludes last decade publications found in the PubMed database. One of the most relevant findings concerningestrogen deprivation was the arterial complacency reduction due to the reduction of elastin, whereas physicalexercises have been widely indicated for the treatment of several cardiovascular disorders and for the hardening of central arteries.

Prevalence of postural deviations in school of educationand professional practice of physical education

This study aimed to verify through postural assessment proposed by Kendall, McCreary and Provance (1990),the prevalence of postural alignment of elementary school students of both sexes, aged between seven andten years. For the definition of the survey, was chosen a private school in the city of Hortolandia - SP wereevaluated in 201 schools. The methodology was the demarcation of the spinous processes of the cervical,thoracic and lumbar vertebrae of the students were evaluated after posterior and lateral views. Data weretabulated and treated statistically. The results showed a high incidence in postural deviations and asymmetriescompared to existing research. It was observed that boys showed an incidence of kyphosis and lordosis higherthan girls and that scoliosis is present in more girls.

Effects of physical exercises on the ventricular myocardium

It is known that people who exercise regularly are less likely to develop heart diseases such as hypertension, obesity, diabetes mellitus, and dyslipidemia decreasing the occurrence of atherosclerosis and its complications: heart failure, stroke, and peripheral vascular disease. In the presence of physical exercises, the myocardium adjusts to the work loads metabolically and mechanically. There are two kinds of physical exercises: aerobic exercise and strength exercise or resistance training. Nowadays, strength exercises have become very popular due to several different reasons. Strength exercises are those performed against a specific opposing gradual resistance to muscular contraction such as weights. According to the literature, both types of exercises have effects on different body tissues. In the present work, a literature review, including scientific articles since 1980, on the effects of aerobic and strength exercises on the ventricular myocardium was conducted. The low and high-intensity strength exercises have different effects, but none of them causes major effects on the cardiovascular function chronically. The most evident alteration of the myocardium subjected to strength exercises is the increase in the cross-sectional area of the cardiac myocytes leading to myocardial hypertrophy.

Structural adaptations of the heart to physical exercises in the metabolic syndrome

The objective of this investigation was to conduct a literature review on the structural adaptations of the heart to physical exercises in the Metabolic Syndrome. The search was conducted in the following electronic databases: PubMed, Web of Sciences, LILLACS and MEDLINE using keywords in English without time restrictions. The metabolic syndrome (MS) is characterized by a group of metabolic risk factors in a person. In Brazil, more than 300.000 people die every year of cardiovascular diseases. According to the Brazilian Ministry of Health, there are currently over 20 million hypertensive and 15 million have diabetes in the country, and this rate is increasing. Physical inactivity, in most individuals, leads to well characterized structural and functional cardiovascular alterations such as myocyte loss with subsequent hypertrophy of the remaining cells and reduction of the arterial complacency. However, the etiology of the cardiovascular alterations is still under investigation. The most likely mechanisms are related to the cumulative harm and several different aggressive factors. Oxidative stress, inflammations, and changes in cardiovascular gene expression seem to influence this system. The benefits of physical exercises have been studied combined with pharmacotherapy offering the opportunity of intervention in the process by using exercises and drugs that can reduce arterial rigidity, cardiac fibrosis, and ventricular hypertrophy.

Dietary sodium intake induced myenteric neuron hypertrophy in Wistar rats

In the present study we investigated the effect of salt intake on myenteric neuron size of the colon of adult male Wistar rats. The animals were placed on either a high-salt (HS; 8 percent; 12 animals) or a low-salt diet (LS; 0.15 percent; 12 animals) for 15 or 52 weeks and blood pressure was measured. The sizes of myenteric neurons of the distal colon from both groups were measured. No difference in neuron size was observed between the HS and LS groups after 15 weeks. After 52 weeks on HS, neuron size was increased (P<0.005) when compared with the LS group. The rats also presented hypertension, which was significantly different at 52 weeks (142 +/- 11 vs 119 +/- 7 mmHg). These results suggest that a long time on an HS diet can significantly increase myenteric nerve cell size.

Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus

The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE) histochemical technique in whole-mount preparations. Neuronal density was 1,500 + 116 neurons/cm2 (mean + SEM) in the esophagus, 8,900 + 1,518 in the stomach, 9,000 + 711 in the jejunum and 13,100 + 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 mum2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease.