Effect of acute swimming exercise at different intensities but equal total load over metabolic and molecular responses in swimming rats

Journal of Muscle Research and Cell Motility - Acute metabolic and molecular response to exercise may vary according to exercise’s intensity and duration. However, there is a lack regarding...     

Comparison of Polar® RS800G3™ heart rate monitor with Polar® S810i™ and electrocardiogram to obtain the series of RR intervals and analysis of heart rate variability at rest

The Polar^® RS800G3^? rate monitor was released in the market to replace the Polar^® S810i^?, and few studies have assessed that the RR series obtained by this equipment is reliable for analysis of heart rate variability (HRV). We compared HRV indexes among the devices Polar^® RS800G3^?, Polar^® S810i^? and eletrocardiogram (ECG) to know whether the series of Polar^® RS800G3^? are as reliable as those devices already validated. We analysed data from 30 healthy young adults, male, with an average age of 20·66 ± 1·40 years, which had captured the heart rate beat to beat in the three devices simultaneously with spontaneously breathing, first in the supine position and subsequently sit both for 30 min. The obtained series of RR intervals was used to calculate the indexes of HRV in the time domain (SDNN and RMSSD) and in the frequency domain (LF, HF and LF/HF). There were no significant differences in HRV indexes calculated from series obtained by the three devices, regardless of the position analysed, and a high correlation coefficient was observed. The results suggest that the Polar^® RS800G3^? is able to capture series of RR intervals for analysis of HRV indexes as reliable as those obtained by ECG and Polar^® S810i^?.     

New poly(ε-caprolactone)/chitosan blend fibers for tissue engineering applications

This study reports for the first time on the production of poly(ε-caprolactone)/chitosan blend fibers for future application as tissue engineering scaffolds. Fibers of chitosan and poly(ε-caprolactone) were prepared by wet spinning from blend solutions, using a formic acid/acetone 70:30 vol.% mixture as common solvent and methanol as coagulant. By this method, blend fibers with a wide compositional range and controllable diameters could be produced. Scanning electron microscopy shows the existence of roughness and porosity at the micron level scale in the blend fiber surface that could be potentially advantageous for cell attachment. Studies were also conducted using both conventional and innovative techniques to evaluate compatibility between the polymers, including FTIR imaging and investigation of the glass transition of chitosan using dynamic mechanical analysis on samples with controlled swelling. The data suggest that a certain degree of interaction exists, although it does not seem to be a result of chemical interaction. The designed fibers could be potentially used for the development of scaffolds for tissue engineering applications.     

Malaria: looking for selection signatures in the human PKLR gene region

The genetic component of susceptibility to malaria is both complex and multigenic and the better‐known protective polymorphisms are those involving erythrocyte‐specific structural proteins and enzymes. In vivo and in vitro data have suggested that pyruvate kinase deficiency, which causes a nonspherocytic haemolytic anaemia, could be protective against malaria severity in humans, but this hypothesis remains to be tested. In the present study, we conducted a combined analysis of Short Tandem Repeats (STRs) and Single Nucleotide Polymorphisms (SNPs) in the pyruvate kinase‐encoding gene (PKLR) and adjacent regions (chromosome 1q21) to look for malaria selective signatures in two sub‐Saharan African populations from Angola and Mozambique, in several groups with different malaria infection outcome. A European population from Portugal, including a control and a pyruvate kinase‐deficient group, was used for comparison. Data from STR and SNP loci spread along the PKLR gene region showed a considerably higher differentiation between African and Portuguese populations than that usually found for neutral markers. In addition, a wider region showing strong linkage disequilibrium was found in an uncomplicated malaria group, and a haplotype was found to be associated with this clinical group. Altogether, this data suggests that malaria selective pressure is acting in this genomic region.     

Tracheostomized patients care: efficacy of a brief theoretical education program for nursing personnel

Introduction  Tracheostomized cancer patients require a special nursing care involving specifically related procedures. The goal of this study was to evaluate the results of a brief theoretical education program on tracheostomized patients care for nursing personnel. Materials and methods  One hundred and ten professionals have participated in this before and after-intervention one group study, and the program was carried out in a Brazilian hospital, a national reference center in oncology treatment. The questionnaire outcomes were compared to assess the theoretical knowledge level of the participants. Results and discussion  Statistical analysis showed that this program was efficient to enhance knowledge skills on specific nursing procedures related to care of the traqueostomized cancer patients. The low costs and simple structure required in the program may encourage the spread of similar practices to improve quality of nursing assistance in the hospital environment.     

Molar incisor hypomineralization in HIV‐infected children and adolescents

The objective was to determine the prevalence of molar incisor hypomineralization (MIH) among individuals between 7 and 15 years old infected or noninfected with human immunodeficiency virus (HIV). The study was conducted with 33 HIV‐infected individuals (study group; SG) and 66 non‐HIV‐infected schoolchildren (control group; CG), paired by gender and age. Data collection was based on medical records (SG), a questionnaire for caregivers and oral examination for diagnosis of MIH (European Academy of Pediatric Dentistry criteria) and caries (DMFT index and ICDAS). Data were analyzed with Mann‐Whitney, chi‐square, and Fisher's exact tests and logistic regression. In SG, MIH (45.5%) and caries (87.9%) had higher prevalence. MIH was associated with use of protease inhibitors in SG (OR: 2.14; 95% CI: 1.21 to 3.77) and incubator need in CG (OR: 2.80; 95% CI: 1.71 to 9.10). HIV‐infected patients had a higher prevalence of MIH and dental caries in the permanent dentition.     

Ethanol withdrawal increases blood pressure and vascular oxidative stress: a role for angiotensin type 1 receptors

We evaluated the possible mechanisms underlying the oxidative stress induced by ethanol withdrawal. With this purpose, we verified the role of AT₁ receptors in such response. Male Wistar rats were treated with ethanol 3%–9% (vol./vol.) for 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 hours after ethanol discontinuation. Increased plasma levels of angiotensin II were detected after ethanol withdrawal. Losartan (10 mg/kg; p.o. gavage), a selective AT₁ receptor antagonist, impeded the increase in blood pressure induced by ethanol withdrawal. Increased lipoperoxidation and superoxide anion (O₂^?) levels were detected in aortas after ethanol withdrawal, and losartan prevented these responses. Decreased hydrogen peroxide and nitrate/nitrite concentration were detected in aortas after ethanol withdrawal, and losartan prevented these effects. Nitrotyrosine immunostaining in the rat aorta was increased after ethanol withdrawal, and AT₁ blockade impeded this response. Increased expression of PKCδ and p47^phox was detected after ethanol withdrawal, and treatment with losartan prevented these responses. Our study provides novel evidence that ethanol withdrawal increases vascular oxidative stress and blood pressure through AT₁-dependent mechanisms. These findings highlight the importance of angiotensin II in ethanol withdrawal–induced increase in blood pressure and vascular oxidative damage.