DETERMINATION OF VIRAL TROPISM BY GENOTYPING AND PHENOTYPING ASSAYS IN BRAZILIAN HIV-1-INFECTED PATIENTS

The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno_[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.     

Resistance Exercise Restores Endothelial Function and Reduces Blood Pressure in Type 1 Diabetic Rats

Background

Resistance exercise effects on cardiovascular parameters are not consistent.

Objectives

The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats.

Methods

Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings.

Results

A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group.

Conclusions

Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats.     

Duke Activity Status Index for Cardiovascular Diseases: Validation of the Portuguese Translation

Background

The Duke Activity Status Index (DASI) assesses the functional capacity of patients with cardiovascular disease (CVD), but there is no Portuguese version validated for CVD.

Objectives

To translate and adapt cross-culturally the DASI for the Portuguese-Brazil language, and to verify its psychometric properties in the assessment of functional capacity of patients with CVD.

Methods

The DASI was translated into Portuguese, then checked by back-translation into English and evaluated by an expert committee. The pre-test version was first evaluated in 30 subjects. The psychometric properties and correlation with exercise testing was performed in a second group of 67 subjects. An exploratory factor analyses was performed in all 97 subjects to verify the construct validity of the DASI.

Results

The intraclass correlation coefficient for test-retest reliability was 0.87 and for the inter-rater reliability was 0.84. Cronbach''s α for internal consistency was 0.93. The concurrent validity was verified by significant positive correlations of DASI scores with the VO₂max (r = 0.51, p < 0.001). The factor analysis yielded two factors, which explained 54% of the total variance, with factor 1 accounting for 40% of the variance. Application of the DASI required between one and three and a half minutes per patient.

Conclusions

The Brazilian version of the DASI appears to be a valid, reliable, fast and easy to administer tool to assess functional capacity among patients with CVD.     

Overspill avalanching in a dense reservoir network

Sustainability of communities, agriculture, and industry is strongly dependent on an effective storage and supply of water resources. In some regions the economic growth has led to a level of water demand that can only be accomplished through efficient reservoir networks. Such infrastructures are not always planned at larger scale but rather made by farmers according to their local needs of irrigation during droughts. Based on extensive data from the upper Jaguaribe basin, one of the world's largest system of reservoirs, located in the Brazilian semiarid northeast, we reveal that surprisingly it self-organizes into a scale-free network exhibiting also a power-law in the distribution of the lakes and avalanches of discharges. With a new self-organized-criticality-type model we manage to explain the novel critical exponents. Implementing a flow model we are able to reproduce the measured overspill evolution providing a tool for catastrophe mitigation and future planning.     

Knowledge of paediatricians regarding child oral health

International Journal of Paediatric Dentistry 2012; 22: 286–291 Background. In dentistry, clinical practice is directed towards attitudes that promote oral health and the paediatricians occupy a privileged position in this process. Aim. To assess the knowledge and attitudes of paediatricians in relation to the oral health of their patients. Design. A cross‐sectional study was carried out at the Institute of Integrative Medicine Professor Fernando Figueira, Recife, Brazil. A total of 182 paediatricians participated by filling out a questionnaire. Results. A total of 63.9% believed the first visit to the dentist should occur before the child completes 1 year of life. Moreover, 67.8% considered their knowledge on oral health to be insufficient. Approximately 78% of the paediatricians diagnosed caries through an analysis of cavities. Only 29.9% always recommended fluoride dentifrice. The term ‘fluorosis’ was unknown by 48.3% of the respondents. Concerning pacifiers, 32.6% did not allow it and 66.9% did not either recommend it or restrict it. A total of 83.4% classified the oral health content in their medical education as either nonexistent or deficient; this figure remained high (72.4%) in relation to residency. Conclusions. It is important to develop oral health information programmes to paediatricians. Information on oral health should be included in medical curricula and residency.     

Decreased phagocytic function in neutrophils and monocytes from peripheral blood in periodontal disease

Phagocytosis by neutrophils and monocytes constitutes the main defense mechanism against bacterial challenges in periodontitis. Phagocytosis by neutrophils has already been evaluated, whereas phagocytic function of monocytes has hardly been addressed so far.

Objectives

The aim of this study was to assess phagocytosis by neutrophils and monocytes in periodontitis.

Material and Methods

The sample included 30 subjects with severe periodontitis and 27 control subjects without periodontal disease. The phagocytic index (PhI) was calculated as the mean number of adhered/ingested Saccharomyces cerevisiae per phagocytozing monocyte or neutrophil multiplied by the percentage of phagocytes involved in phagocytosis.

Results

A significant reduction in phagocyte functions was observed in individuals with periodontitis. The median of PhI of neutrophils using non-sensitized S. cerevisiae was 3 for the control group, and 1.5 for the periodontitis group (p=0.01, Mann-Whitney test). The median of PhI of monocytes with non-sensitized S. cerevisiae was 26.13 for the control group, and 13.23 for the periodontitis group (p=0.03, Mann Whitney test). The median of PhI of monocytes assessed with sensitized S. cerevisiae was 97.92 for the control group and 60.1 for the periodontitis group (p=0.005, t-test).

Conclusion

The data demonstrated a reduction in the function of phagocytes, suggesting a decrease in immune defenses in periodontitis.     

Elevated plasma levels and platelet-associated expression of the pro-thrombotic and pro-inflammatory protein, TNFSF14 (LIGHT), in sickle cell disease

Chronic vascular inflammation and endothelial activation may initiate vaso‐occlusion in sickle cell disease (SCD). TNFSF14 (CD258; LIGHT), a recently‐identified pro‐thrombotic and pro‐inflammatory tumour necrosis factor (TNF)‐superfamily cytokine, has a potent activating effect on endothelial cells. We evaluated whether TNFSF14 production is altered in SCD and whether platelets contribute to this production. TNFSF14 was measured in platelet‐free plasma from healthy‐control individuals (CON), steady‐state sickle cell anaemia (SCA), SCA on hydroxycarbamide therapy (SCAHC) and haemoglobin SC (HbSC) patients. Mean plasma TNFSF14 was significantly increased in SCA, SCAHC and HbSC, compared to CON individuals. In SCA/SCAHC patients, plasma TNFSF14, showed no correlation with haematological variables, but was significantly correlated with serum lactate dehydrogenase and inflammatory markers (CD40LG , IL8 and ICAM1). Platelet‐membrane TNFSF14 expression was significantly augmented on SCA platelets, and correlated with platelet activation; furthermore, measurement of platelet TNFSF14 release indicated that platelets may be a major source of circulating TNFSF14 in SCA. Interestingly, high plasma TNFSF14 was significantly associated with elevated tricuspid regurgitant velocity (≥2·5 m/s) in a population of SCA/SCAHC patients. The pro‐inflammatory and atherogenic cytokine, TNFSF14, could contribute to endothelial activation and inflammation in SCA; future investigations may confirm whether this protein contributes to major clinical complications of the disease, such as pulmonary hypertension, and represents a potential therapeutic target.