Roberta Lins Gonçalves

The flavonoid dioclein is a selective inhibitor of cyclic nucleotide phosphodiesterase type 1 (PDE1) and a cGMP-dependent protein kinase (PKG) vasorelaxant in human vascular tissue.

The inhibitory effect of the flavonoid dioclein was assessed on purified vascular cyclic nucleotide phosphodiesterase isoforms (EC 3.1.4.17, PDE1-5) in comparison with 8-methoxymethyl-isobutylmethylxanthine (8-MM-IBMX) and vinpocetine which are currently used as PDE1 inhibitors. The mechanism underlying the vasorelaxant effect of dioclein was investigated in human saphenous vein. Dioclein inhibited PDE1 more selectively than vinpocetine and 8-MM-IBMX, with IC(50) values of 2.47+/-0.26 and 1.44+/-0.35 microM, respectively in basal- and calmodulin-activated states. Dioclein behaved as a competitive inhibitor for cGMP hydrolysis by PDE1 in basal- and calmodulin-activated states (K(i)=0.62+/-0.14 and 0.55+/-0.07 microM, respectively), indicating this inhibitory effect to be independent of calmodulin interactions. In addition, dioclein induced a concentration-dependent relaxation of human saphenous vein which was independent on the presence of functional endothelium (EC(50) values of 7.3+/-3.1 and 11+/-2.7 microM, respectively with and without endothelium). 8-MM-IBMX relaxed human saphenous vein with an EC(50)=31+/-16 microM, whereas vinpocetine did not cause any vasorelaxation at concentrations up to 100 microM. Rp-8-pCPT-cGMPS, which inhibits cGMP-dependent protein kinase (PKG), blocked the vasodilator effect of dioclein, whereas H-89, which is a cAMP-dependent protein kinase (PKA) inhibitor, had a minor inhibitory effect. Our data show that dioclein is a potent calmodulin-independent selective inhibitor of PDE1 and that inhibition of PDE1 is involved in the PKG-mediated vasorelaxant effect of dioclein in human saphenous vein. Furthermore, dioclein may represent a new archetype to develop more specific PDE1 inhibitors.

Endotracheal suctioning in intubated newborns: an integrative literature review

Evidence-based practices search for the best available scientific evidence to support problem solving and decision making. Because of the complexity and amount of information related to health care, the results of methodologically sound scientific papers must be integrated by performing literature reviews. Although endotracheal suctioning is the most frequently performed invasive procedure in intubated newborns in neonatal intensive care units, few Brazilian studies of good methodological quality have examined this practice, and a national consensus or standardization of this technique is lacking. Therefore, the purpose of this study was to review secondary studies on the subject to establish recommendations for endotracheal suctioning in intubated newborns and promote the adoption of best-practice concepts when conducting this procedure. An integrative literature review was performed, and the recommendations of this study are to only perform endotracheal suctioning in newborns when there are signs of tracheal secretions and to avoid routinely performing the procedure. In addition, endotracheal suctioning should be conducted by at least two people, the suctioning time should be less than 15 seconds, the negative suction pressure should be below 100 mmHg, and hyperoxygenation should not be used on a routine basis. If indicated, oxygenation is recommended with an inspired oxygen fraction value that is 10 to 20% greater than the value of the previous fraction, and it should be performed 30 to 60 seconds before, during and 1 minute after the procedure. Saline instillation should not be performed routinely, and the standards for invasive procedures must be respected.

Predictive equations for respiratory muscle strength by anthropometric variables

Recent studies have pointed out divergences in the predictive quality of reference equations for respiratory muscle strength, alerting the need to introduce into these equation‐specific variables for certain target populations.

Cardiorespiratory Repercussions of Hot Tub (Ofurô) in Preterm Newbornswith Low Birth Weight: A Cross-Sectional Study

Background: According to the World Health Organization preterm birth is the most common direct cause of newborn mortality. Preterm birth and being small for gestational age which are the reasons for low-birth-weight (LBW), are also important indirect causes of neonatal deaths. LBW contributes to 60% to 80% of all neonatal deaths. In addition to the high mortality rate preterm newborns (PTNB), especially LBW, there are many barriers to the normal development. In this way, some practices have been adopted to favor the humanized assistance to the baby and his family. The hot tub, known in Brazil as ofuro, has been use in Brazil as a form of aquatic physiotherapy with the purpose of contributing to the reduction of stress, length of hospital stay and favoring the weight gain of PTNB with LBW. It consists of immersing the PTNB in hot tub in warm water up to shoulder height to simulate the sensation of the mothers uterus. However, there are few studies evaluating the repercussions of the subject. Objective: To evaluate the cardiorespiratory repercussions heart rate, respiratory rate, oxygen pulse saturation and the pain of PTNB submitted to the hot tub were observed. Methodological design: A prospective cross-sectional study was carried out in an intermediate care unit of Manaus, Amazonas, Brazil, between Months from March to November 2016. Twenty-one PTNB which have undergone to the hot tub were observed in three moments: before (moment 1), during (moment 2) and after (moment 3) hot tub. Categorical variables were evaluated by frequency, percentages, and the numerical by means of mean, median and standard deviation. 0.05 of significance was adopted. Results: The hot tub did not present cardiorespiratory changes in the PTNB analyzed and did not cause pain or stress or any type of intercurrence. Clinically there was a favorable response to conduct. It was possible to observe that the PTNB during the hot tub remained calm and relaxed, and in many situations, they presented sleepiness and yawning demonstrating well-being with the conduct. Conclusion: The hot tub did not present cardiorespiratory alterations in the low birth weight PTNB analyzed and did not cause pain, stress, or any kind of intercurrence, being a safe conduct in this regard.

Neuronal nitric oxide synthase-derived hydrogen peroxide effect in grafts used in human coronary bypass surgery

Recently, H2O2 has been identified as the endothelium-dependent hyperpolarizing factor (EDHF), which mediates flow-induced dilation in human coronary arteries. Neuronal nitric oxide synthase (nNOS) is expressed in the cardiovascular system and, besides NO, generates H2O2 The role of nNOS-derived H2O2 in human vessels is so far unknown. The present study was aimed at investigating the relevance of nNOS/H2O2 signaling in the human internal mammary artery (IMA) and saphenous vein (SV), the major conduits used in coronary artery bypass grafting. In the IMA, but not in the SV, ACh (acetylcholine)-induced vasodilatation was decreased by selective nNOS inhibition with TRIM or Inhibitor 1, and by catalase, which specifically decomposes H2O2 Superoxide dismutase (SOD), which generates H2O2 from superoxide, decreased the vasodilator effect of ACh on SV. In the IMA, SOD diminished phenylephrine-induced contraction in endothelium-containing, but not in endothelium-denuded vessels. Importantly, while exogenous H2O2 produced vasodilatation in IMA, it constricted SV. ACh increased H2O2 production in both sets of vessels. In the IMA, the increase in H2O2 was inhibited by catalase and nNOS blockade. In SV, H2O2 production was abolished by catalase and reduced by nNOS inhibition. Immunofluorescence experiments showed the presence of nNOS in the vascular endothelium and smooth muscle cells of both the IMA and SV. Together, our results clearly show that H2O2 induced endothelium-dependent vascular relaxation in the IMA, whereas, in the SV, H2O2 was a vasoconstrictor. Thus, H2O2 produced in the coronary circulation may contribute to the susceptibility to accelerated atherosclerosis and progressive failure of the SV used as autogenous graft in coronary bypass surgery.

COMPARATIVE STUDY OF MAXIMUM RESPIRATORY PRESSURE IN ADULTS FROM AMAZONAS BY DIFFERENT PREDICTIVE EQUATIONS

Introduction: The measurement of muscular strength and maximum static pressures, substantially a consecrated and practical method, raise discussions about reference values and predictive equations, taking into account the heterogeneity of the studies. Objectives: Compare predicted values of IPmax and EPmax with the equations of Neder et al., 1999 and Costa et al., 2010 in adult individuals from the state of Amazonas (AM, Brazil). Method: A cross-sectional study in which was evaluated the Maximum Respiratory Pressures (IPmax and EPmax) according to standardization of the Brazilian Society of Pneumology and Tisiology in 210 individuals (68% female and 32% male) and 109 were eutrophic and 101 with overweight. The age of the individuals was 47,8±18,5 years. For comparative statistical analysis between the values obtained and predicted by the equations was performed the Anova One Way - Software SigmaStat 3.5 test. Results: The comparison of the values obtained with those predicted revealed that the Neder et al underestimated the IPmax in both genders (P <0,001) and overestimated the EPmax in males (P <0,001). While the equation of Costa et al overestimated the IPmax and EPmax in males (P <0,001) underestimated the IPmax in females (P<0,001). Conclusion: The results evidenced divergences in the predictive quality of the equations used, especially for IPmax, which suggests the low specificity of it in the population evaluated.

Respiratory Function and the Influence of Inspiratory Muscle in Vital Capacity inParkinsons Disease

Background: Pulmonary disorders have been identified in Parkinsons disease (PD) since its description. They are associated with high mortality. However, there have been limited investigations on respiratory function in the patients with PD. The mechanisms mediating this association need to be better clarified. The relationship between maximal inspiratory pressure (MIP) and the forced vital capacity (FVC) in these individuals has not been investigated yet. Objective: The objective was to assess and compare the respiratory function in older elderly with and without PD in order to determine the prevalence of respiratory dysfunction and the influence of MIP in FCV. Methodological design: Cross-sectional study which evaluated 41 elderly with PD and 41 elderly without (control group). Inclusion criteria: For patients with PD: level of disability 0-3 Hoehn and Yahr scale and levodopa substitution therapy. For all participants: more than 60 years, no smoking, and no diagnosis of respiratory dysfunction and have physical and cognitive conditions to perform the tests. Pulmonary function was investigated by spirometry and MIP through manovacuometry. For the comparison between the groups was used the Students t test and Mann Whitney and the correlation between the variables of interest was investigated by linear regression model. Results: There was a higher prevalence of respiratory disorder in patients with PD, whose major ventilation dysfunction was restrictive. There were significantly lower values % FVC and forced expiratory volume in the first minute (FEV1) in patients with PD and a direct association between FVC and MIP. This association can only be observed in the control group in the elderly who presented restrictive disturbance. Conclusion: Patients with PD showed important modifications of pulmonary function even in the early stages of the disease. Thus, the pulmonary evaluation must be systematically performed in subjects with PD and the impact of pulmonary rehabilitation on these dysfunctions should be the focus of further research.