Marcos C. Borges

Evaluation of Cardiac Involvement During Dengue Viral Infection

BACKGROUND  Dengue is a disease whose clinical manifestations range from asymptomatic infections to a severe disease. There have been some previous reports of myocardial involvement in dengue, but this association has not been completely established. METHODS  From January to July of 2011, patients hospitalized with dengue, confirmed through dengue nonstructural protein 1 and/or immunoglobulin M detection, were included in this study and troponin I and N terminal fragment of B-type natriuretic peptide levels were determined. Patients with abnormal biomarkers underwent echocardiography and when any abnormality was detected, they underwent cardiac magnetic resonance imaging. RESULTS  Eighty-one patients were evaluated and 12 patients (15%) presented with elevated biomarker levels. Compared to controls, they had higher leukocyte (P < .001) and platelet counts (P = .005); higher C-reactive protein (P = .02), and a lower viral load (P = .03). There was no difference according to clinical dengue classification; dengue hemorrhagic fever/dengue shock syndrome severity; duration of symptoms; or prevalence of secondary infection between the 2 groups. Two patients died secondary to cardiogenic shock before imaging studies. Necroscopic findings were compatible to myocarditis in both, and immunohistochemistry for dengue virus showed increased staining on mononuclear cells located in the myocardial tissue. Of the 10 patients who underwent echocardiography, depressed left ventricular ejection fraction (LVEF) was identified in 1, left ventricular segmental abnormalities with preserved LVEF in 2, and an important pericardial effusion with tamponade in another. Cardiac involvement was confirmed by CMR in these 4 patients. CONCLUSIONS  Dengue viruses were shown to cause cardiac disease with clinical manifestations ranging from mild elevation of biomarkers to myocarditis and/or pericarditis.

Clinical evaluation of the NS1 antigen‐capture ELISA for early diagnosis of dengue virus infection in Brazil

The fact that the diagnosis of infection with dengue virus is usually made by detecting IgM antibodies during the convalescent phase of the disease interferes with disease management and, consequently, with reducing mortality rates. This study evaluated the sensitivity and specificity of detection of NS1 in samples of patients suspected of acute dengue virus infection in Brazil. The results were used to institute treatment and the sensitivity and specificity of detection of NS1 were compared to the results of detection of IgM, virus isolation, and RT‐PCR. Detection of NS1 yielded better results than RT‐PCR and virus isolation. When considering IgM detection and RT‐PCR positive results as “gold standards,” the sensitivity and specificity of the NS1 assay were 95.9% and 81.1%, respectively. All patients enrolled in the study were treated promptly and had an uneventful course of the disease. The detection of NS1 provided better results than the diagnostic techniques used currently during the acute phase of disease (RT‐PCR and virus isolation). Detection of NS1 is an important tool for the diagnosis of acute dengue infection, particularly in highly endemic areas, allowing for rapid treatment of patients and reduction of disease burden. J. Med. Virol. 82:1400–1405, 2010.

IL-33 contributes to sepsis-induced long-term immunosuppression by expanding the regulatory T cell population

Patients who survive sepsis can develop long-term immune dysfunction, with expansion of the regulatory T (Treg) cell population. However, how Treg cells proliferate in these patients is not clear. Here we show that IL-33 has a major function in the induction of this immunosuppression. Mice deficient in ST2 (IL-33R) develop attenuated immunosuppression in cases that survive sepsis, whereas treatment of naive wild-type mice with IL-33 induces immunosuppression. IL-33, released during tissue injury in sepsis, activates type 2 innate lymphoid cells, which promote polarization of M2 macrophages, thereby enhancing expansion of the Treg cell population via IL-10. Moreover, sepsis-surviving patients have more Treg cells, IL-33 and IL-10 in their peripheral blood. Our study suggests that targeting IL-33 may be an effective treatment for sepsis-induced immunosuppression.

A role for decorin in a murine model of allergen-induced asthma

Decorin (Dcn) is an extracellular matrix proteoglycan, which affects airway mechanics, airway-parenchymal interdependence, airway smooth muscle proliferation and apoptosis, and transforming growth factor-β bioavailability. As Dcn deposition is differentially altered in asthma, we questioned whether Dcn deficiency would impact the development of allergen-induced asthma in a mouse model. Dcn(-/-) and Dcn(+/+) mice (C57Bl/6) were sensitized with ovalbumin (OA) and challenged intranasally 3 days/wk × 3 wk. After OA challenge, mice were anesthetized, and respiratory mechanics measured under baseline conditions and after delivery of increasing concentrations of methacholine aerosol. Complex impedance was partitioned into airway resistance and tissue elastance and damping. Bronchoalveolar lavage was performed. Lungs were excised, and tissue sections evaluated for inflammatory cell influx, α-smooth muscle actin, collagen, biglycan, and Dcn deposition. Changes in TH-2 cytokine mRNA and protein were also measured. Airway resistance was increased in OA-challenged Dcn(+/+) mice only (P < 0.05), whereas tissue elastance and damping were increased in both OA-challenged Dcn(+/+) and Dcn(-/-), but more so in Dcn(+/+) mice (P < 0.001). Inflammation and collagen staining within the airway wall were increased with OA in Dcn(+/+) only (P < 0.001 and P < 0.01, respectively, vs. saline). IL-5 and IL-13 mRNA were increased in lung tissue of OA-challenged Dcn(+/+) mice. Dcn deficiency resulted in more modest OA-induced hyperresponsiveness, evident at the level of the central airways and distal lung. Differences in physiology were accompanied by differences in inflammation and remodeling. These findings may be, in part, due to the well-described ability of Dcn to bind transforming growth factor-β and render it less bioavailable.

Investigação de fatores associados à asma de difícil controle

OBJECTIVE To determine the prevalence of factors associated with difficult-to-control asthma. METHODS Patients with severe asthma were selected from the outpatient asthma clinic of the Ribeirão Preto School of Medicine Hospital das Clínicas. The patients were divided into two groups: controlled severe asthma and difficult-to-control severe asthma. After new attempts to optimize the severe asthma treatment, a questionnaire was applied, and additional tests for factors associated with difficult-to-control asthma, such as environmental and occupational exposure, smoking history, social factors, rhinitis/sinusitis, gastroesophageal reflux disease (GERD), obstructive sleep apnea, congestive heart failure (CHF), pulmonary embolism, cystic fibrosis, vocal cord dysfunction, alpha-1 antitrypsin deficiency, and Churg-Strauss syndrome, were performed. RESULTS 77 patients with severe asthma were selected, of which 47 suffered from hard-to-control asthma, being 68.1% female, with mean age of 44.4 years (+/-14.4), and forced expiratory volume in one second of 54.7% (+/-18.3). The most factors most often associated with difficult-to-control asthma were noncompliance with treatment (68%), rhinitis/sinusitis (57%), GERD (49%), environmental exposure (34%), occupational exposure (17%), smoking history (10%), obstructive sleep apnea (2%), and CHF (2%). At least one of these factors was identified in every case. CONCLUSIONS Noncompliance with treatment was the factor most often associated with difficult-to-control asthma, underscoring the need to investigate comorbidities in the evaluation of patients with this form of the disease.

Comparison of 4 AM and 4 PM Bronchial Responsiveness to Hypertonic Saline in Asthma

Bronchial responsiveness to methacholine or histamine increases at night and may contribute to the mechanisms of nocturnal asthma. Hypertonic saline (HS) is a more clinically relevant stimulus for the diagnosis and assessment of the severity of asthma, but the circadian variation in bronchial responsiveness to hypertonic challenges has not been addressed. The aim of this study was to compare the responsiveness to hypertonic saline at 4:00 AM and at 4:00 PM. Eighteen diurnally active patients (11 women) with asthma, 31 ± 9 years of age (mean ± SD) and with a forced expiratory volume in 1 s (FEV1) of 79.11% ± 12.85%, underwent two challenge tests (4:00 AM and 4:00 PM) in random sequence separated by an interval of 7 days. The challenge test consisted of inhalations of 4.5% saline with increasing doses by doubling the duration of nebulization (0.5, 1, 2, 4, and 8 min). The inhalation continued until a drop of 20% in FEV1 was achieved or total time of 15.5 min. The provocative dose that caused the 20% drop in FEV1 (PD20) was calculated. Differences were found between 4:00 PM and 4:00 AM values for inhalation times [3.80 ± 3.57 min and 2.19 ± 2.42 min (p = 0.001), respectively] and for PD20 [4.94 ± 6.77 ml and 2.93 ± 4.74 ml (p = 0.002), respectively]. Eight patients with a home-assessed nocturnal peak expiratory flow (PEF) drop of more than 15% formed the nocturnal asthma group. The behavior of these patients was similar to that of the non-nocturnal asthma group. We conclude that the bronchial responsiveness to HS increases at night.

Influence of Nocturnal Asthma on Chronotype

Individual differences in circadian rhythm have been studied since the past century. Chronotypes are a chronobiology classification based on the preferential times for beginning and ending activities throughout the day. Chronotypes can be classified as definitely morning, moderately morning, indifferent, moderately evening, and definitely evening. We aim to assess the distribution of chronotypes in asthmatics and the relationship of chronotype to the presence of nocturnal symptoms. Two hundred subjects were evaluated, 100 asthmatics and 100 non-asthmatics. The Morningness/Eveningness questionnaire was applied for chronotype determination. The asthmatics were subdivided according to the presence or absence of nocturnal symptoms. The chronotype distribution did not differ significantly between asthmatics and non-asthmatics. Thirty-five percent of the asthma group reported nocturnal symptoms. There was a significant difference in chronotype distribution between asthmatics with and without nocturnal worsening. The asthmatics with nocturnal symptoms had a lower prevalence of morning types and had a greater predominance of indifferent chronotype compared to asthmatics without nocturnal symptoms (p = 0.011). In conclusion, asthmatics with nocturnal symptoms present deviation from the chronotype distribution curve when compared to asthmatics without nocturnal symptoms. This is the first study to show the effect of a disease on chronotypes.

Evaluation of the endothelial glycocalyx damage in patients with acute coronary syndrome

BACKGROUND Endothelial glycocalyx (EG) is sugar-based cell-bound surface molecules linked to transmembrane proteins observed on the endothelial surface of the vessels. Damage to this structure causes an increase in platelet and leucocyte adhesion and shear stress in the vessel. We hypothesized a possible link between EG damage and acute coronary syndrome (ACS). METHODS We measured the syndecan-1 levels (a biomarker of EG damage) in 141 patients (99 men) with ACS and compared to those of 45 patients (24 men) with non-coronary chest pain (NCCP) and of 24 (14 men) healthy individuals (CONTROL). RESULTS The baseline characteristics of the ACS and NCCP groups were similar. Syndecan-1 levels were significantly higher in the ACS group than in the NCCP (p = 0.01) and CONTROL (p = 0.001) groups but did not differ between the NCCP and CONTROL groups (p = 0.83). In analysis according to gender category, the difference among the groups remained significant only for men (p = 0.0009). A syndecan-1 level higher than 148 ng/ml was associated with ACS diagnosis with an odds ratio of 14 (95% confidence interval (CI): 1.8 to 102), p = 0.011. After adjusting for gender, age and current or past tobacco use, this syndecan-1 level remained positively associated with ACS diagnosis with an odds ratio of 12 (95% CI: 1.6 to 93), p = 0.016. CONCLUSION Higher syndecan-1 levels were observed during ACS, mostly in men, suggesting that EG damage could participate in the atherosclerotic plaque vulnerability process in these patients.

A standardized methanol extract of Eclipta prostrata (L.) L. (Asteraceae) reduces bronchial hyperresponsiveness and production of Th2 cytokines in a murine model of asthma

ETHNOPHARMACOLOGICAL RELEVANCE Eclipta prostrata (L.) L. (Asteraceae) has been used in Brazilian traditional medicine to treat asthma and other respiratory illnesses. AIMS OF THE STUDY To investigate the effects of different doses of a standardized extract of E. prostrata using a murine model of allergen induced asthma. MATERIALS AND METHODS Balb/c mice were sensitized twice with ovalbumin (OVA) administered intraperitoneally and challenged over four alternate days with nasal instillations of OVA solution. The standardized methanol extract of E. prostrata was administered in doses of 100, 250 and 500mgkg-1 concomitantly with nasal instillation over seven consecutive days. Control animals were treated with dexamethasone or saline solution. Bronchial hyperresponsiveness, production of Th1 and Th2 cytokines, allergen sensitization, airway and lung inflammation, mucous secretion and airway remodeling were assessed. RESULTS The concentrations of chemical markers in the standardized methanol extract were 0.02% oroboside, 1.69% demethylwedelolactone and 1.71% wedelolactone. Treatment with 250mgkg-1 of extract, which provided 0.745, 4.22 and 4.30mgkg-1day-1 of oroboside, demethylwedelolactone and wedelolactone, respectively, significantly reduced (P<0.05) respiratory resistance and elastance. Such effects were comparable with those produced by dexamethasone. The total number of inflammatory cells and eosinophils in the bronchoalveolar lavage and the concentrations of interleukin (IL)-4, IL-5 and IL-13 in lung homogenate were significantly reduced (P<0.05) by the methanol extract of E. prostrata. CONCLUSION The results presented herein demonstrate for the first time the anti-inflammatory activity of E. prostrata in a murine model of asthma, thereby supporting the ethnopharmacological uses of the plant.

Development and validation of an asthma knowledge questionnaire for use in Brazil

OBJECTIVE To develop and validate an asthma knowledge questionnaire for use in adult asthma patients in Brazil. METHODS A 34-item self-report questionnaire was constructed and administered to adult asthma patients and adult controls. The maximum total score was 34. RESULTS The questionnaire was shown to be discriminatory, with good reliability and reproducibility. The mean score for asthma patients and controls was, respectively, 21.47 +/- 4.11 (range: 9-31) and 17.27 +/- 5.11 (range: 7-28; p < 0.001). The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.53, and the Bartletts test of sphericity demonstrated a satisfactory suitability of the data to factor analysis (p < 0.001). There was no significant difference between the total scores obtained in the first and in the second application of the questionnaire within a two-week interval (p = 0.43). The internal consistency reliability (KR-20 coefficient) was 0.69. CONCLUSIONS This study has validated an asthma knowledge questionnaire for use in Brazil.