Swimming training attenuates the decrease of calcium responsiveness in female infarcted rats.

To evaluate the influence of swimming training on calcium responsiveness of the myocardium of rats with different infarction sizes (MI). female Wistar rats, sedentary sham (SS = 14), sedentary moderate MI (SMI = 8) and sedentary large MI (SLI = 10) were compared to trained sham (TS = 16), trained moderate MI (TMI = 9) and trained large MI (TLI = 10). After 4 weeks of MI, the animals swam for 60 min/day, 5 days/week, for additional 8 weeks.

Haemophilia A: health and economic burden of a rare disease in Portugal.

Background: Haemophilia A is a hereditary bleeding disorder, which has been considered rare and chronic. The burden of this disease in Portugal remains unknown. The aim of this study was to estimate the annualized cost and health burden of haemophilia A in Portugal.

Delayed Reperfusion-Coronary Artery Reperfusion Close to Complete Myocardial Necrosis Benefits Remote Myocardium and Is Enhanced by Exercise.

The present study aimed to analyze the effects of reperfusion of a distant coronary artery on cardiac function, the ultrastructure, and the molecular environment of the remote myocardium immediately after the completion of myocardial regional necrosis: delayed reperfusion (DR). Additionally, the effects of prior exercise on the outcomes of DR were investigated. Female rats with permanent occlusion or delayed reperfusion were randomly assigned to an exercise (swimming, 1 h/day, 5 days/week for 8 weeks) or sedentary protocol.

Predicted Equation for VO2 Based on a 20-Meter Multistage Shuttle Run Test for Children.

This study compared maximum oxygen consumption (VOmax) on a 20-meter multistage shuttle run test (20-Srt) with a cardiopulmonary exercise test (CPET) to determine a VOmax prediction equation for a 20-Srt in children aged 6-10 years. Eighty healthy children performed the CPET on a treadmill, while the 20-Srt took place on a sports court. Heart rate (HR) was measured and the expired gases were continuously measured breath-by-breath using a portable gas analyzer.

Paradoxical Sleep Deprivation Causes Cardiac Dysfunction and the Impairment Is Attenuated by Resistance Training.

Background: Paradoxical sleep deprivation activates the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, subsequently interfering with the cardiovascular system. The beneficial effects of resistance training are related to hemodynamic, metabolic and hormonal homeostasis. We hypothesized that resistance training can prevent the cardiac remodeling and dysfunction caused by paradoxical sleep deprivation.

Are there gender differences in left ventricular remodeling after myocardial infarction in rats?

Objective: An unclear issue is whether gender may influence at cardiac remodeling after myocardial infarction (MI). We evaluated left ventricle remodeling in female and male rats post-MI.

Methods: Rats were submitted to anterior descending coronary occlusion.

Expression of MicroRNA-29 and Collagen in Cardiac Muscle after Swimming Training in Myocardial-Infarcted Rats.

Background: Myocardial infarction (MI) is accompanied by cardiac growth, increased collagen deposition, cell death and new vascularization of the cardiac tissue, which results in reduced ventricular compliance. The MiRNA-29 family (29a, 29b, and 29c) targets mRNAs that encode collagens and other proteins involved in fibrosis. In this study we assessed the effects of swimming training (ST) on expression of the cardiac miRNA-29 family and on genes encoding collagen after MI in rats.

Cell therapy prevents structural, functional and molecular remodeling of remote non-infarcted myocardium.

Background/objectives: Therapy using bone marrow (BM) cells has been tested experimentally and clinically due to the potential ability to restore cardiac function by regenerating lost myocytes or increasing the survival of tissues at risk after myocardial infarction (MI). In this study we aimed to evaluate whether BM-derived mononuclear cell (MNC) implantation can positively influence the post-MI structural remodeling, contractility and Ca(2+)-handling proteins of the remote non-infarcted tissue in rats.

Methods And Results: After 48 h of MI induction, saline or BM-MNC were injected.

Cardiac implications after myocardial infarction in rats previously undergoing physical exercise.

Background: Few studies have analyzed the cardiac effects of exercise prior to coronary occlusion.

Objective: To evaluate the effects of myocardial infarction in rats undergoing physical exercise.

Methods: Female rats underwent swimming exercise or were kept sedentary for eight weeks and were randomized to coronary occlusion or sham surgery, in one of the following four groups: Sedentary (S), exercise (E), Sedentary myocardial infarction (SMI) and Exercise myocardial infarction (EMI).

Myocardial remodeling after large infarcts in rat converts post rest-potentiation in force decay.

Background: Post-rest contraction (PRC) of cardiac muscle provides indirect information about the intracellular calcium handling.

Objective: Our aim was to study the behavior of PRC, and its underlying mechanisms, in rats with myocardial infarction.

Methods: Six weeks after coronary occlusion, the contractility of papillary muscles (PM) obtained from sham-operated (C, n=17), moderate infarcted (MMI, n=10) and large infarcted (LMI, n=14) rats was evaluated, following rest intervals of 10 to 60 seconds before and after incubation with lithium chloride (Li(+)) substituting sodium chloride or ryanodine (Ry).

Severity of the cardiac impairment determines whether digitalis prolongs or reduces survival of rats with heart failure due to myocardial infarction.

Background: The aim of the present study was to evaluate if the influence of digitalis on survival depends on the severity of cardiac dysfunction in heart failure (HF).

Methods And Results: Doppler echocardiogram (DE) parameters were analyzed in 84 Wistar control (C) and 80 Wistar rats treated with 0.1mg/100g/day of digitoxin (D) five days after coronary occlusion.

Rat adipose tissue-derived stem cells transplantation attenuates cardiac dysfunction post infarction and biopolymers enhance cell retention.

Background: Cardiac cell transplantation is compromised by low cell retention and poor graft viability. Here, the effects of co-injecting adipose tissue-derived stem cells (ASCs) with biopolymers on cell cardiac retention, ventricular morphometry and performance were evaluated in a rat model of myocardial infarction (MI).

Methodology/principal Findings: 99mTc-labeled ASCs (1x10(6) cells) isolated from isogenic Lewis rats were injected 24 hours post-MI using fibrin a, collagen (ASC/C), or culture medium (ASC/M) as vehicle, and cell body distribution was assessed 24 hours later by gamma-emission counting of harvested organs.

Exercise training inhibits inflammatory cytokines and more than prevents myocardial dysfunction in rats with sustained beta-adrenergic hyperactivity.

Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex).

Digitoxin prolongs survival of female rats with heart failure due to large myocardial infarction.

Background: We analyzed whether digitoxin affects the survival of rats with congestive heart failure.

Methods And Results: The influence of digitoxin (0.1 mg.

Left ventricle radio-frequency ablation in the rat: a new model of heart failure due to myocardial infarction homogeneous in size and low in mortality.

Background: The purpose of the current study was to create a model of myocardial infarction (MI) that is homogeneous in size with a low immediate (24 hours) mortality.

Methods And Results: Male and female rats (n = 256) underwent left ventricle (LV) ablation (Ab) by a radiofrequency current (1000 kHz; 12 watts for 12 seconds) to promote a MI. A transmural MI occurred in all rats.

Bone marrow cell therapy prevents infarct expansion and improves border zone remodeling after coronary occlusion in rats.

Background: Since the cell therapy benefits for myocardial infarction are mainly related to infarct reduction by regenerating lost myocardium or increasing survival of tissues at risk, we evaluated the effects of bone marrow-derived mononuclear cells (MNC), implanted after the completion of necrosis, on infarct progression and cardiac remodeling.

Methods: After 48 h of induction of myocardial infarction (MI), Lewis-inbred rats were injected with 6 × 10(6) cells (MI+MNC) or saline (MI). After six weeks, scar dimension, ventricular morphology and function were analyzed by echocardiography followed by histomorphology of the infarcted and border zones.

Doppler echocardiographic predictors of mortality in female rats after myocardial infarction.

Background: Doppler echocardiogram is useful for the evaluation of anatomical and functional changes in late myocardial infarction (MI) in rats. However, no studies have evaluated the prognostic value of echocardiographic parameters 1 week after MI.

Methods And Results: Doppler echocardiogram was performed in 84 female Wistar rats 1 week after MI to determine infarction size, left chambers dimensions, fractional area change (FAC) of the left ventricle (LV), mitral inflow and tissue Doppler, myocardial performance index (MPI), and signs of pulmonary hypertension.