Aline Cristina Tavares

Biological activity of ruthenium nitrosyl complexes.

Nitric oxide plays an important role in various biological processes, such as neurotransmission, blood pressure control, immunological responses, and antioxidant action. The control of its local concentration, which is crucial for obtaining the desired effect, can be achieved with exogenous NO-carriers. Coordination compounds, in particular ruthenium(III) and (II) amines, are good NO-captors and -deliverers. The chemical and photochemical properties of several ruthenium amine complexes as NO-carriers in vitro and in vivo have been reviewed. These nitrosyl complexes can stimulate mice hippocampus slices, promote the lowering of blood pressure in several in vitro and in vivo models, and control Trypanosoma cruzi and Leishmania major infections, and they are also effective against tumor cells in different models of cancer. These complexes can be activated chemically or photochemically, and the observed biological effects can be attributed to the presence of NO in the compound. Their efficiencies are explained on the basis of the [Ru(II)NO(+)](3+)/[Ru(II)NO(0)](2+) reduction potential, the specific rate constant for NO liberation from the [RuNO](2+) moiety, and the quantum yield of NO release.

Effects of short-term heated water-based exercise training on systemic blood pressure in patients with resistant hypertension: a pilot study.

High blood pressure (BP) increases the risk of cardiovascular diseases, and its control is a clinical challenge. Regular exercise lowers BP in patients with mild-to-moderate hypertension. No data are available on the effects of heated water-based exercise in hypertensive patients. Our objective was to evaluate the effects of heated water-based exercise on BP in patients with resistant hypertension. We tested the effects of 60-min heated water-based exercise training three times per week in 16 patients with resistant hypertension (age 55±6 years). The protocol included walking and callisthenic exercises. All patients underwent 24-h ambulatory blood pressure monitoring (ABPM) before and after a 2-week exercise program in a heated pool. Systolic office BP was reduced from 162 to 144 mmHg (P<0.004) after heated-water training. After the heated-water exercise training during 24-h ABPM, systolic BP decreased from 135 to 123 mmHg (P=0.02), diastolic BP decreased from 83 to 74 mmHg (P=0.001), daytime systolic BP decreased from 141 to 125 mmHg (P=0.02), diastolic BP decreased from 87 to 77 mmHg (P=0.009), night-time systolic BP decreased from 128 to 118 mmHg (P=0.06), and diastolic BP decreased from 77 to 69 mmHg (P=0.01). In addition, BP cardiovascular load was reduced significantly during the 24-h daytime and night-time period after the heated water-based exercise. Heated water-based exercise reduced office BP and 24-h daytime and night-time ABPM levels. These effects suggest that heated water-based exercise may have a potential as a new therapeutic approach to resistant hypertensive patients.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients.

BACKGROUNDnHypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients.nnnMETHODSn40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX).nnnRESULTSnThe ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p < 0.01) and daytime (4.8 ± 1.6 mm Hg, p < 0.01) systolic ABP, and 24-hour (7.0 ± 1.4 mm Hg, p < 0.001) daytime (7.5 ± 1.6 mm Hg, p < 0.001) and nighttime (5.9 ± 1.5 mm Hg, p < 0.001) diastolic ABP after the intervention. The ET group also had improved Vo2MAX (9.7% ± 2.6%, p < 0.001) after the intervention. However, PWV did not change after ET. No variable was changed in the control group after the intervention.nnnCONCLUSIONSnThe 12-week ET program was effective for reducing ABP but not PWV in heart transplant recipients. This result suggests that endurance ET may be a tool to counteract hypertension in this high-risk population.

Antitubercular activity of Ru (II) isoniazid complexes.

Despite the resistance developed by the Mycobacterium tuberculosis (MTb) strains, isoniazid (INH) has been recognized as one of the best drug for treatment of Tuberculosis (Tb). The coordination of INH to ruthenium metal centers was investigated as a strategy to enhance the activity of this drug against the sensitive and resistant strains of MTb. The complexes trans-[Ru(NH3)4(L)(INH)](2+) (L=SO2 or NH3) were isolated and their chemical and antituberculosis properties studied. The minimal inhibitory concentration (MIC) data show that [Ru(NH3)5(INH)](2+) was active in both resistant and sensitive strains, whereas free INH (non-coordinated) showed to be active only against the sensitive strain. The coordination of INH to the metal center in both [Ru(NH3)5(INH)](2+) and trans-[Ru(NH3)4(SO2)(INH)](2+) complexes led to a shift in the INH oxidation potential to less positive values compared to free INH. Despite, the ease of oxidation of INH did not lead to an increase in the in vitro INH activity against MTb, it might have provided sensitivity toward resistant strains. Furthermore, ruthenium complexes with chemical structures analogous to those described above were synthesized using the oxidation products of INH as ligands (namely, isonicotinic acid and isonicotinamide). These last compounds were not active against any strains of MTb. Moreover, according to DFT calculations the formation of the acyl radical, a proposed intermediate in the INH oxidation, is favored in the [Ru(NH3)5(INH)](2+) complex by 50.7kcalmol(-1) with respect to the free INH. This result suggests that the stabilization of the acyl radical promoted by the metal center would be a more important feature than the oxidation potential of the INH for the antituberculosis activity against resistant strains.

Endothelial function in pre-pubertal children at risk of developing cardiomyopathy: a new frontier

Although it is known that obesity, diabetes, and Kawasakis disease play important roles in systemic inflammation and in the development of both endothelial dysfunction and cardiomyopathy, there is a lack of data regarding the endothelial function of pre-pubertal children suffering from cardiomyopathy. In this study, we performed a systematic review of the literature on pre-pubertal children at risk of developing cardiomyopathy to assess the endothelial function of pre-pubertal children at risk of developing cardiomyopathy. We searched the published literature indexed in PubMed, Bireme and SciELO using the keywords ‘endothelial, ‘children, ‘pediatric and ‘infant and then compiled a systematic review. The end points were age, the pubertal stage, sex differences, the method used for the endothelial evaluation and the endothelial values themselves. No studies on children with cardiomyopathy were found. Only 11 papers were selected for our complete analysis, where these included reports on the flow-mediated percentage dilatation, the values of which were 9.80±1.80, 5.90±1.29, 4.50±0.70, and 7.10±1.27 for healthy, obese, diabetic and pre-pubertal children with Kawasakis disease, respectively. There was no significant difference in the dilatation, independent of the endothelium, either among the groups or between the genders for both of the measurements in children; similar results have been found in adolescents and adults. The endothelial function in cardiomyopathic children remains unclear because of the lack of data; nevertheless, the known dysfunctions in children with obesity, type 1 diabetes and Kawasakis disease may influence the severity of the cardiovascular symptoms, the prognosis, and the mortality rate. The results of this study encourage future research into the consequences of endothelial dysfunction in pre-pubertal children.

Effects of age on aerobic capacity in heart failure patients under beta-blocker therapy: Possible impact in clinical decision-making?

BACKGROUNDnHeart failure (HF) is associated with impaired maximal aerobic capacity as indicated by decreases in peak oxygen uptake (peak VO(2)). Considering that aging by itself has a negative effect on this variable, the evaluation of maximum capacity is often questioned because current predicted peak VO(2) is based on subjects without heart disease or b-blocker therapy. In contrast, if decline in predicted and attained peak VO(2) were age-related, proportionally, loss of aerobic function (predicted peak VO(2), %) would remain stable over time in these patients. The purpose of this investigation is to assess the effects of age on peak VO(2) in HF patients taking b-blockers.nnnMETHODSnWe retrospectively evaluated 483 (132 female) patients (aged 20-88 years, LVEF 31 ± 11%) with non-ischemic (n = 362), ischemic (n = 74) and Chagas-related HF (n = 47) who had been submitted to an incremental cardiopulmonary exercise testing on a motorized treadmill. Linear regression was used to develop the equation to predict peak VO(2), based on age.nnnRESULTSnPeak VO(2) decreased 0.9 mL/min/kg per age-decade, maximum HR also decreased with aging and VE/VCO(2) slope was similar among all decades. The predicted new b-blocker equation to peak VO(2 bb) was 20.934 - 0.092 × age.nnnCONCLUSIONSnClinical interpretation of aerobic capacity impairment is influenced by aging in HF patients. This evidence must be considered when using peak VO(2) for prognostic stratification and clinical decision-making in patients with HF under b-blocker therapy.

Functional Class in Children with Idiopathic Dilated Cardiomyopathy. A pilot Study

Background Idiopathic dilated cardiomyopathy (IDCM), most common cardiac cause of pediatric deaths, mortality descriptor: a low left ventricular ejection fraction (LVEF) and low functional capacity (FC). FC is never self reported by children. Objective The aims of this study were (i) To evaluate whether functional classifications according to the children, parents and medical staff were associated. (iv) To evaluate whether there was correlation between VO2 max and Webers classification. Method Prepubertal children with IDCM and HF (by previous IDCM and preserved LVEF) were selected, evaluated and compared. All children were assessed by testing, CPET and functional class classification. Results Chi-square test showed association between a CFm and CFp (1, n = 31) = 20.6; p = 0.002. There was no significant association between CFp and CFc (1, n = 31) = 6.7; p = 0.4. CFm and CFc were not associated as well (1, n = 31) = 1.7; p = 0.8. Webers classification was associated to CFm (1, n = 19) = 11.8; p = 0.003, to CFp (1, n = 19) = 20.4; p = 0.0001and CFc (1, n = 19) = 6.4; p = 0.04). Conclusion Drawing were helpful for childrens self NYHA classification, which were associated to Webers stratification.

A Five-day Orthostatic Training Program Improves CardiovascularResponse in Intensive Care Patients

Objective: To evaluate the cardiovascular response to passive orthostatic training. n nMethod: Intensive care patients were recruited. Patients in Control group underwent conventional physical therapy. Patients in the Training group additionally underwent daily assistive standing training with the use of an orthostatic bed for five days. All patients in the Training group were evaluated while on the orthostatic table (at rest for 10 minutes, at 75 degrees of inclination for 40 minutes and after returning to the supine position). Heart rate and mean arterial pressure were assessed at each stage. Both groups were assessed at baseline and after seven days. n nResults: After the 5-day intervention patients from Control group had their mean arterial pressure decreased significantly (19 mmHg in average) when compared to baseline mean arterial pressure at the moment they had their body position elevated, with the worsening of postural hypotension in the following minutes, pattern which not found in the Training group patients. n nConclusion: A five-day orthostatic training in intensive care patients can be safely performed and improves cardiovascular response.