Aerobic exercise training prevents skeletal myopathy by myomiRs regulation in heart failure

Introduction

Heart failure (HF) is the endpoint of systemic arterial hypertension. Exercise intolerance is a common symptom, partly due, to changes in the skeletal muscle mass (SM) and fiber type profile. Otherwise, aerobic exercise training (ET) has been used as an important non-pharmacological therapy in HF. MyomiRs are a muscle-specific class of miRNAs, which regulate genes that inhibiting the expression of proteins in pathological and physiological conditions controlling phenotypic changes in the SM, however little is known about these changes in ET-induced HF

Purpose

To elucidate the molecular mechanisms of ET involved in the metabolic alterations of SM in HF rats of hypertensive etiology.

Methods

The study was approved by the animal ethics committee (USP-No. 2020/01). 20 male rats, spontaneously hypertensive (SHR), and 10 Wistar Kyoto rats (WKY), SHR controls, nine-months-old, were divided into three groups: sedentary WKY (WKY-S), sedentary SHR (SHR-S), and trained (SHR-T). The ET consisted of swimming sessions with 60 minutes, 1x/day, 5x/week, for 10 weeks, with 5% of body overload. After ET protocol, blood pressure (BP), cardiac morphology and function (Echocardiography), exercise tolerance test, maximal oxygen uptake (VO2 peak), mitochondrial oxygen consumption (Oroboros), immunohistochemistry of the SM, expression of miRNAs (RT-qPCR) were evaluated. Statistical analyzes were performed by one-way ANOVA followed by the Tukey test. The results were expressed as mean ± standard error.

Results

ET reduced blood pressure levels and cardiac dysfunction in SHR-T compared to SHR-S. The SHR-S group covered smaller distance in the exercise tolerance test (255±22 meters) compared to the WKY-S (419±19 meters, p<0.0001), however ET reestablished the exercise tolerance (SHR-T: 365±20 meters; SHR-S: p<0.001 and WKY-S: p>0.05). The HF induced changes in type I and II fibers composition (I: 73±0.6% and II: 24±0.9%), VO2 peak (50±1.5 mL kg–1 min–1), mitochondrial oxygen consumption (State 3: 3.0±0.2 nmol O2 min–1 mg protein–1) and myomiRs expression (miRNA-208b: 65±4%, -499: 73±5%, -1: 153±10%) in the soleus muscle of SHR-S compared to WKY-S (I: 94±0.6%, II: 6±0.6%, p<0.001; VO2 peak: 59±2.3 mL kg–1 min–1, p<0.01; State 3: 4.0±0.2 nmol O2 min–1 mg protein–1, p<0.05; miRNAs: p<0.01). ET minimized changes in metabolic profile by counteract the muscle fiber type switching, and the oxygen consumption impairment, and myomiRs expression dysregulation (I: 90±0.5%, II: 9±0.6%, SHR-S p<0.01; VO2 peak: 79±2.4 mL kg–1 min–1, SHR-S: p<0.0001; State 3: 5.45±0.32 nmol O2 min–1 mg protein–1, SHR-S: p<0.0001; miRNA-208b: 91±5%, -499: 106±8%, -1: 100±9%; SHR-S: p<0.01).

Conclusions

ET reestablished structural and metabolic changes in SM, resulting from the progression of HF, through the regulation of myomiRs, improving exercise tolerance.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Coordination for the Improvement of Higher Education Personnel (CAPES): Academic Excellence Program (Proex).

Correlates of children's physical activity during the COVID-19 confinement in Portugal

OBJECTIVES

The aim of the study was to understand the role of household variables on the percentage of physical activity (%PA) during the coronavirus disease 2019 (COVID-19) confinement in Portugal.

STUDY DESIGN

A cross-sectional study design using an anonymous online survey was launched to assess how Portuguese families with children aged younger than 13 years adjusted their daily routines to the confinement.

METHODS

Separate analyses of variance were performed to investigate how factors such as the number of children, age, sex, the housing characteristics, and the adults' job situation can affect the percentage of time for PA (%PA).

RESULTS

Findings, based on data from 2159 children, indicate that (1) boys and girls did not differ in the %PA on any of the age-groups; (2) children with an outdoor space and who had other children in the household were significantly more active (P < .001); (3) children from families with all adults working from home showed lower levels of %PA; and (4) being younger, having a big outdoor space, having other children in the household, and having at least one adult free from working from home were significant positive predictors of children's %PA, explaining 21% of the overall variance.

CONCLUSION

Time allocated for PA during this period is reduced compared with what is usually reported on normal days. It is necessary to find strategies to increase children's PA, especially in families in which both parents are working and have no outdoor space.

Body mass index and motor coordination: Non-linear relationships in children 6-10 years

BACKGROUND

Given the concern for health-related consequences of an elevated body mass index (BMI; obesity), the potential consequences of a low BMI in children are often overlooked. The purpose was to evaluate the relationship between the BMI across its entire spectrum and motor coordination (MC) in children 6-10 years.

METHODS

Height, weight, and MC (Körperkoordinationstest für Kinder, KTK test battery) were measured in 1,912 boys and 1,826 girls of 6-10 years of age. BMI (kg/m² ) was calculated. KTK scores for each of the four tests were also converted to a motor quotient (MQ). One-way ANOVA was used to test differences in the BMI, individual test items, and MQ among boys and girls within age groups. Sex-specific quadratic regressions of individual KTK items and the MQ on the BMI were calculated. Girls and boys were also classified into four weight status groups using International Obesity Task Force criteria: thin, normal, overweight, and obese. Differences in specific test items and MQ between weight status groups were evaluated by age group in each sex.

RESULTS

Thirty-one percent of the sample was overweight or obese, whereas 5% was thin. On average, normal weight children had the highest MQ in both sexes across the age range with few exceptions. Overweight/obese children had a lower MQ than normal weight and thin children. The quadratic regression lines generally presented an inverted parabolic relationship between the BMI and MC and suggested a decrease in MC with an increase in the BMI.

CONCLUSION

In general, BMI shows a curvilinear, inverted parabolic relationship with MC in children 6-10 years.

Human dental pulp stem cells transplantation combined with treadmill training in rats after traumatic spinal cord injury

Spinal cord injury (SCI) is a disabling condition resulting in deficits of sensory and motor functions, and has no effective treatment. Considering that protocols with stem cell transplantation and treadmill training have shown promising results, the present study evaluated the effectiveness of stem cells from human exfoliated deciduous teeth (SHEDs) transplantation combined with treadmill training in rats with experimental spinal cord injury. Fifty-four Wistar rats were spinalized using NYU impactor. The rats were randomly distributed into 5 groups: Sham (laminectomy with no SCI, n=10); SCI (laminectomy followed by SCI, n=12); SHEDs (SCI treated with SHEDs, n=11); TT (SCI treated with treadmill training, n=11); SHEDs+TT (SCI treated with SHEDs and treadmill training; n=10). Treatment with SHEDs alone or in combination with treadmill training promoted functional recovery, reaching scores of 15 and 14, respectively, in the BBB scale, being different from the SCI group, which reached 11. SHEDs treatment was able to reduce the cystic cavity area and glial scar, increase neurofilament. Treadmill training alone had no functional effectiveness or tissue effects. In a second experiment, the SHEDs transplantation reduced the TNF-α levels in the cord tissue measured 6 h after the injury. Contrary to our hypothesis, treadmill training either alone or in combination, caused no functional improvement. However, SHEDs showed to be neuroprotective, by the reduction of TNF-α levels, the cystic cavity and the glial scar associated with the improvement of motor function after SCI. These results provide evidence that grafted SHEDs might be an effective therapy to spinal cord lesions, with possible anti-inflammatory action.

Validity and reliability of a pictorial instrument for assessing perceived motor competence in Portuguese children

BACKGROUND

It is important to assess young children's perceived Fundamental Movement Skill (FMS) competence in order to examine the role of perceived FMS competence in motivation toward physical activity. Children's perceptions of motor competence may vary according to the culture/country of origin; therefore, it is also important to measure perceptions in different cultural contexts. The purpose was to assess the face validity, internal consistency, test-retest reliability and construct validity of the 12 FMS items in the Pictorial Scale for Perceived Movement Skill Competence for Young Children (PMSC) in a Portuguese sample.

METHODS

Two hundred one Portuguese children (girls, n = 112), 5 to 10 years of age (7.6 ± 1.4), participated. All children completed the PMSC once. Ordinal alpha assessed internal consistency. A random subsamples (n = 47) were reassessed one week later to determine test-retest reliability with Bland-Altman method. Children were asked questions after the second administration to determine face validity. Construct validity was assessed on the whole sample with a Bayesian Structural Equation Modelling (BSEM) approach. The hypothesized theoretical model used the 12 items and two hypothesized factors: object control and locomotor skills.

RESULTS

The majority of children correctly identified the skills and could understand most of the pictures. Test-retest reliability analysis was good, with an agreement ration between 0.99 and 1.02. Ordinal alpha values ranged from acceptable (object control 0.73, locomotor 0.68) to good (all FMS 0.81). The hypothesized BSEM model had an adequate fit.

CONCLUSIONS

The PMSC can be used to investigate perceptions of children's FMS competence. This instrument can also be satisfactorily used among Portuguese children.

Weight status is associated with cross-sectional trajectories of motor co-ordination across childhood

BACKGROUND

Research indicates the development of motor co-ordination (MC) may be an important contributing factor to positive or negative weight trajectories across childhood.

OBJECTIVES

To analyse cross-sectional associations between MC and weight status in children (boys n = 3344 - girls n = 3281), aged 6-11 years and assess overweight/obese risk across different ages.

METHODS

Body mass index (BMI) was calculated [body mass (kg)/height (m(2))]. MC was evaluated using the Körperkoordination Test für Kinder (KTK) and a motor quotient (MQ) was calculated. MQ distribution data were split into tertiles. The effect of age, sex and MQ tertiles on BMI and MC was tested with a factorial anova. A logistic regression also was performed to calculate odd ratios (OR) for being overweight/obese at each age.

RESULTS

Children with higher MQ demonstrated lower BMI levels (F(2,6224) = 222.09; P < 0.001). Differences in BMI among MQ tertiles became larger across age (F(10,6224) = 4.53; P < 0.001). The OR of being overweight/obese in both sexes within the lowest MQ tertile increased in each age group from 6 to 11 years. Specifically, OR increased from 2.26 to 27.77 and from 1.87 to 6.81 in boys and girls respectively.

CONCLUSIONS

Children with low levels of MC have a higher risk of being overweight/obese and this risk increases with age.

Transplantation of mononuclear cells from human umbilical cord blood promotes functional recovery after traumatic spinal cord injury in Wistar rats

Cell transplantation is a promising experimental treatment for spinal cord injury. The aim of the present study was to evaluate the efficacy of mononuclear cells from human umbilical cord blood in promoting functional recovery when transplanted after a contusion spinal cord injury. Female Wistar rats (12 weeks old) were submitted to spinal injury with a MASCIS impactor and divided into 4 groups: control, surgical control, spinal cord injury, and one cell-treated lesion group. Mononuclear cells from umbilical cord blood of human male neonates were transplanted in two experiments: a) 1 h after surgery, into the injury site at a concentration of 5 x 10⁶ cells diluted in 10 µL 0.9% NaCl (N = 8-10 per group); b) into the cisterna magna, 9 days after lesion at a concentration of 5 x 10⁶ cells diluted in 150 µL 0.9% NaCl (N = 12-14 per group). The transplanted animals were immunosuppressed with cyclosporin-A (10 mg/kg per day). The BBB scale was used to evaluate motor behavior and the injury site was analyzed with immunofluorescent markers to label human transplanted cells, oligodendrocytes, neurons, and astrocytes. Spinal cord injury rats had 25% loss of cord tissue and cell treatment did not affect lesion extension. Transplanted cells survived in the injured area for 6 weeks after the procedure and both transplanted groups showed better motor recovery than the untreated ones (P < 0.05). The transplantation of mononuclear cells from human umbilical cord blood promoted functional recovery with no evidence of cell differentiation.

Motor coordination as predictor of physical activity in childhood

This study considers relationships among motor coordination (MC), physical fitness (PF) and physical activity (PA) in children followed longitudinally from 6 to 10 years. It is hypothesized that MC is a significant and primary predictor of PA in children. Subjects were 142 girls and 143 boys. Height, weight and skinfolds; PA (Godin-Shephard questionnaire); MC (Körperkoordination Test für Kinder); and PF (five fitness items) were measured. Hierarchical linear modeling with MC and PF as predictors of PA was used. The retained model indicated that PA at baseline differed significantly between boys (48.3 MET/week) and girls (40.0 MET/week). The interaction of MC and 1 mile run/walk had a positive influence on level of PA. The general trend for a decrease in PA level across years was attenuated or amplified depending on initial level of MC. The estimated rate of decline in PA was negligible for children with higher levels of MC at 6 years, but was augmented by 2.58 and 2.47 units each year, respectively, for children with low and average levels of initial MC. In conclusion MC is an important predictor of PA in children 6-10 years of age.

Effects of xenoestrogen bisphenol A on uterine and pituitary weight, serum prolactin levels and immunoreactive prolactin cells in ovariectomized Wistar rats

Considerable attention has currently been focused on bisphenol A (BPA), an environmental endocrine disrupting chemical that has oestrogenic activity. In vitro and in vivo short-term assays have shown that BPA is weakly estrogenic. In addition, the issue of species- and strain-differences in susceptibility to BPA was raised. The treatment of ovariectomized (OVX) Wistar rats with BPA at doses of 11-250 mg/kg per day, s.c., for 7 days, resulted in significant dose-dependent regrowth of uterus in uterotrophic assay. Additionally, the stimulation of anterior pituitary gland growth and induction of hyperprolactinaemia, as determined by wet organ weight and radioimmunoassay (RIA), respectively, were also dose-dependent (at 128 and 250 mg/kg per day, P < 0.05). Prolactin immunostaining of anterior pituitary glands revealed that BPA at a dose of 250 mg/kg per day increased the number of prolactin-immunopositive cells by 63% compared to OVX rats. These results demonstrate that the reproductive tract and neuroendocrine axis of Wistar rats are able to respond to BPA. Furthermore, the pituitary gland hypertrophy and hyperprolactinaemia can be mediated, at least partly, by increase in number of prolactin-immunoreactive cells. The long-term consequences of this proliferation are yet unknown but neoplasm formation is an obvious possibility.

[Attitudes towards scientific research among nursing students from 3 schools from the Sao Paulo countryside]

The nursing research among undergraduate students develop the logical and critical thinking that are important to the professional. So, it is necessary to have content about research in the beginning of the undergraduate courses. The quantitative study identified the attitudes about nursing research of the undergraduate students. It was investigated 248 undergraduate students of the 1o., 3o. 8o. semesters in three nursing schools of the São Paulo State. It was utilized Likert Scales as a instrument of data collection. The results showed that the students have responsible attitudes of the research. The students from the 1o. semesters are less conscious about the results of research comparable to the intuition and personal experience. They are interested in of discuss the results of the research with colleagues. Most of the students agree that is fundamental to conduct research with the faulty members.

[Teaching of scientific methods in eight nursing schools of the south east region of Brazil]

Few are the courses of professional formation in nursing that consider teaching activities of the scientific method in the nursing curriculum. This qualitative study identified the real situation of eight undergraduate courses of the southeast region related to the teaching of scientific method. We conclude that, in schools, the discipline in study is compulsory, being denominated Methodology of Nursing Research. The analysed content includes the phases of the research project and the teaching strategy employed was the lecture classes. The evaluations employed were: critical analysis of scientific texts and individual texts. Teachers indicated the importance of a monography at the end of the course and an option for the division of the content in two disciplines with a schedule of 45 hours each.