VITOR BRITO DA SILVA
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conferenceObject PARATHYROIDECTOMY MAY IMPAIR PHYSIOLOGIC SYSTEMIC VASOCONSTRICTION AFTER HEMODIALYSIS PROCEDURE(2014) FREITAS, Geraldo R.; SILVA, Vitor B.; ABENSUR, Hugo; LUDERS, Claudio; PEREIRA, Benedito J.; CASTRO, Manuel C. M.; OLIVERIRA, Rodrigo B.; MOYSES, Rosa M. A.; ELIAS, Rosilene M.; SILVA, Bruno C.- Chronic exposure of diesel exhaust particles induces alveolar enlargement in mice(2015) YOSHIZAKI, Kelly; BRITO, Jose Mara; MORIYA, Henrique T.; TOLEDO, Alessandra C.; FERZILAN, Sandra; OLIVEIRA, Ana Paula Ligeiro de; MACHADO, Isabel D.; FARSKY, Sandra H. P.; SILVA, Luiz F. F.; MARTINS, Milton A.; SALDIVA, Paulo H. N.; MAUAD, Thais; MACCHIONE, MariangelaBackground: Diesel exhaust particles (DEPs) are deposited into the respiratory tract and are thought to be a risk factor for the development of diseases of the respiratory system. In healthy individuals, the timing and mechanisms of respiratory tract injuries caused by chronic exposure to air pollution remain to be clarified. Methods: We evaluated the effects of chronic exposure to DEP at doses below those found in a typical bus corridor in Sao Paulo (150 mu g/m(3)). Male BALB/c mice were divided into mice receiving a nasal instillation: saline (saline; n = 30) and 30 mu g/10 mu L of DEP (DEP; n = 30). Nasal instillations were performed five days a week, over a period of 90 days. Bronchoalveolar lavage (BAL) was performed, and the concentrations of interleukin (IL)-4, IL-10, IL-13 and interferon-gamma (INF-gamma) were determined by ELISA-immunoassay. Assessment of respiratory mechanics was performed. The gene expression of Muc5ac in lung was evaluated by RT-PCR. The presence of IL-13, MAC2+ macrophages, CD3+, CD4+, CD8+ T cells and CD20+ B cells in tissues was analysed by immunohistochemistry. Bronchial thickness and the collagen/elastic fibers density were evaluated by morphometry. We measured the mean linear intercept (Lm), a measure of alveolar distension, and the mean airspace diameter (D0) and statistical distribution (D2). Results: DEP decreased IFN-gamma levels in BAL (p = 0.03), but did not significantly alter IL-4, IL-10 and IL-13 levels. MAC2+ macrophage, CD4+ T cell and CD20+ B cell numbers were not altered; however, numbers of CD3+ T cells (p <= 0.001) and CD8+ T cells (p <= 0.001) increased in the parenchyma. Although IL-13 (p = 0.008) expression decreased in the bronchiolar epithelium, Muc5ac gene expression was not altered in the lung of DEP-exposed animals. Although respiratory mechanics, elastic and collagen density were not modified, the mean linear intercept (Lm) was increased in the DEP-exposed animals (p <= 0.001), and the index D2 was statistically different (p = 0.038) from the control animals. Conclusion: Our data suggest that nasal instillation of low doses of DEP over a period of 90 days results in alveolar enlargement in the pulmonary parenchyma of healthy mice.
- Hemodynamic Behavior During Hemo-dialysis: Effects of Dialysate Concentrations of Bicarbonate and Potassium(2014) SILVA, Bruno C.; FREITAS, Geraldo R. R.; SILVA, Vitor B.; ABENSUR, Hugo; LUDERS, Claudio; PEREIRA, Benedito J.; OLIVEIRA, Rodrigo B. de; CASTRO, Manuel C. M.; MOYSES, Rosa M. A.; ELIAS, Rosilene M.Background/Aims: Ultrafiltration that occurs during hemodialysis (HD) promotes profound alterations in a relatively short period of time. The dialysate content of bicarbonate (DBic) and potassium (DK) may have impact over intradialytic hemodynamics, which goes beyond ultrafiltration, and its impact was evaluated in a prospective cohort. Methods: 30 patients under HD were submitted to hemodynamic assessment (HA) at the beginning and at the end of HD sessions, through a non-invasive method. Serum minus dialysate potassium concentration was expressed as K-Gap. Cardiac index (CI) and peripheral arterial resistance (PAR) variation (post-HD minus pre-HD) were expressed as Delta CI and Delta PAR. Dialysate content of sodium and calcium were expressed as DNa and DCa, respectively. Results: Mean DNa, DK and DBic were, respectively, 136.4 +/- 1.1, 2.1 +/- 0.6 and 38.2 +/- 2.1 mEq/L. In 15 patients, DCa was > 1.5 mmol/L and in the other 15 patients <= 1.5 mmol/L. The K-Gap ranged from 1.4 to 5.1 mEq/l (median 3.0 mEq/L). There was a reduction in post-HD CI and systolic blood pressure (Delta CI = -0.72l/min/m(2) and -11.3 +/- 15.1 mmHg, respectively, p < 0.001 for both). Conversely, Delta PAR increased (Delta PAR = 272dyn.s/cm(5), p < 0.001). Lower post-HD CI was was associated to higher DBic (p = 0.0013) and lower K-Gap (p = 0.026). In multivariate analysis, Delta CI was dependent on DBic and K-Gap, whereas Delta PAR was dependent on dialysate calcium during HD. Conclusion: We confirmed that Na and Ca dialysate content exerts and important role on hemodynamic during HD. In addition, our findings pointed out that higher dialysate concentrations of bicarbonate and potassium promote lower cardiac performance at the end of hemodialysis session.
- Parathyroidectomized patients have impaired capacity of peripheral vascular constriction during hemodialysis(2016) SILVA, Bruno C.; MOYSES, Rosa M. A.; SILVA, Vitor B.; FREITAS, Geraldo R. R.; ELIAS, Rosilene M.Parathyroidectomy (PTx) seems to improve cardiovascular outcomes and reduce blood pressure levels. However, the effect of PTx on hemodynamic changes during hemodialysis (HD) is still overlooked. This was a prospective cohort design. Patients with end-stage renal disease on maintenance HD were included. Diabetes and nonsinusal rhythm were exclusion criteria. History of PTx was recorded. Finometer monitor was used to access parameters immediately pre- and post-HD sessions. Cardiac index (CI) variation (CI) and peripheral arterial resistance variation (PAR) were the variables of interest. Biochemical and echocardiographic data were also obtained. PTx patients (n=11) were matched to non-PTx patients (n=20). PAR was lower in PTx group in comparison with non-PTx group (P=0.039), which was independent of parathyroid hormone (PTH) levels. Multiple regression analysis showed that PTx, CI, and dialysate calcium remained independently associated with PAR variation and even adjusted for ultrafiltration rate (adjusted r(2)=0.64). In conclusion, parathyroidectomized patients have impaired capacity of vasoconstriction in response to ultrafiltration, an effect independent of serum PTH levels. Further studies are needed to elucidate mechanisms explaining the interaction between PTx and systemic vascular tonus.
- Organic and Inorganic Fractions of Diesel Exhaust Particles Produce Changes in Mucin Profile of Mouse Trachea Explants(2015) SERIANI, Robson; JUNQUEIRA, Mara S.; TOLEDO, Alessandra C.; CORREA, Aristides T.; SILVA, Luiz F. F.; MARTINS, Milton A.; SALDIVA, Paulo H. N.; MAUAD, Thais; MACCHIONE, MariangelaDiesel exhaust particles (DEP) contain organic and inorganic elements that produce damage to the respiratory epithelium. The aim of this study was to determine the mucus profile of tracheal explants exposed to either crude diesel exhaust particles (DEP) or DEP treated with nitric acid (DEP/NA), with hexane (DEP/HEX), or with methanol (DEP/MET) at concentrations of 50 and 100 mu g/ml for 30 and 60 min. Tracheal explants were subjected to morphometric analyses to study acidic (AB+), neutral (PAS+), and mixed (AB+/PAS+) mucus production and vacuolization (V). Incubation with 50 mu g/ml crude DEP resulted in a rise in acid mucus production, an increase in vacuolization at 30 min, and reduction in neutral mucus at 30 and 60 min. Tracheas exposed to DEP/MET at 50 mu g/ml for 30 or 60 min resulted in a significant decrease in neutral mucus production and an elevation in acid mucus production. DEP/HEX increased vacuolization at both 50 and 100 mu g/ml at 30 and 60 min of exposure. Treatment with 50 mu g/ml for 30 or 60 min significantly elevated mixed mucus levels. These results suggest that DEP appear to be more toxic when administered in combination with HEX or MET. DEP/MET modified the mucus profile of the epithelium, while DEP/HEX altered mucus extrusion, and these responses might be due to bioavailability of individual elements in DEP fractions.
- High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function(2019) SILVA, V. B.; MACEDO, T. A.; BRAGA, T. M. S.; SILVA, B. C.; GRACIOLLI, F. G.; V, W. Dominguez; DRAGER, L. F.; MOYSES, R. M.; ELIAS, R. M.Dialysate calcium concentration (d[Ca]) might have a cardiovascular impact in patients on haemodialysis (HD) since a higher d[Ca] determines better hemodynamic tolerability. We have assessed the influence of d[Ca] on global longitudinal strain (GLS) by two-dimensional echocardiography using speckle-tracking imaging before and in the last hour of HD. This is an observational crossover study using d[Ca] 1.75 mmol/L and 1.25 mmol/L. Ultrafiltration was the same between interventions; patients aged 44 +/- 13 years (N = 19). The 1.75 mmol/L d[Ca] was associated with lighter drop of blood pressure. Post HD serum total calcium was higher with d[Ca] 1.75 than with 1.25 mmol/L (11.5 +/- 0.8 vs. 9.1 +/- 0.5 mg/dL, respectively, p < 0.01). In almost all segments strain values were significantly worse in the peak HD with 1.75 mmol/L d[Ca] than with 1.25 mmol/L d[Ca]. GLS decreased from -19.8 +/- 3.7% at baseline to -17.3 +/- 2.9% and -16.1 +/- 2.6% with 1.25 d[Ca] and 1.75 d[Ca] mmol/L, respectively (p < 0.05 for both d[Ca] vs. baseline and 1.25 d[Ca] vs. 1.75 d[Ca] mmol/L). Factors associated with a worse GLS included transferrin, C-reactive protein, weight lost, and post dialysis serum total calcium. We concluded that d[Ca] of 1.75 mmol/L was associated with higher post dialysis serum calcium, which contributed to a worse ventricular performance. Whether this finding would lead to myocardial stunning needs further investigation.