THALES DE BRITO
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LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina
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- Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage(2018) BRAGANCA, Ana C. de; MOREAU, Regina L. M.; BRITO, Thales de; SHIMIZU, Maria H. M.; CANALE, Daniele; JESUS, Denise A. de; SILVA, Ana M. G.; GOIS, Pedro H.; SEGURO, Antonio C.; MAGALDI, Antonio J.
- Regression of Albuminuria and Hypertension and Arrest of Severe Renal Injury by a Losartan-Hydrochlorothiazide Association in a Model of Very Advanced Nephropathy(2013) ARIAS, Simone Costa Alarcon; VALENTE, Carla Perez; MACHADO, Flavia Gomes; FANELLI, Camilla; ORIGASSA, Clarice Silvia Taemi; BRITO, Thales de; CAMARA, Niels Olsen Saraiva; MALHEIROS, Denise Maria Avancini Costa; ZATZ, Roberto; FUJIHARA, Clarice KazueTreatments that effectively prevent chronic kidney disease (CKD) when initiated early often yield disappointing results when started at more advanced phases. We examined the long-term evolution of renal injury in the 5/6 nephrectomy model (Nx) and the effect of an association between an AT-1 receptor blocker, losartan (L), and hydrochlorothiazide (H), shown previously to be effective when started one month after Nx. Adult male Munich-Wistar rats underwent Nx, being divided into four groups: Nx+V, no treatment; Nx+L, receiving L monotherapy; Nx+LH, receiving the L+H association (LH), and Nx+AHHz, treated with the calcium channel blocker, amlodipine, the vascular relaxant, hydralazine, and H. This latter group served to assess the effect of lowering blood pressure (BP). Rats undergoing sham nephrectomy (S) were also studied. In a first protocol, treatments were initiated 60 days after Nx, when CKD is at a relatively early stage. In a second protocol, treatments were started 120 days after Nx, when glomerulosclerosis and interstitial fibrosis are already advanced. In both protocols, L treatment promoted only partial renoprotection, whereas LH brought BP, albuminuria, tubulointerstitial cell proliferation and plasma aldosterone below pretreatment levels, and completely detained progression of renal injury. Despite normalizing BP, the AHHz association failed to prevent renal damage, indicating that the renoprotective effect of LH was not due to a systemic hemodynamic action. These findings are inconsistent with the contention that thiazides are innocuous in advanced CKD. In Nx, LH promotes effective renoprotection even at advanced stages by mechanisms that may involve anti-inflammatory and intrarenal hemodynamic effects, but seem not to require BP normalization.
- Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage(2017) BRAGANCA, Ana C. de; MOREAU, Regina L. M.; BRITO, Thales de; SHIMIZU, Maria H. M.; CANALE, Daniele; JESUS, Denise A. de; SILVA, Ana M. G.; GOIS, Pedro H.; SEGURO, Antonio C.; MAGALDI, Antonio J.Background Ecstasy (Ec) use produces hyperthermia, excessive sweating, intense thirst, an inappropriate antidiuretic hormone secretion (SIADH) and a multisystemic toxicity due to oxidative stress (OS). Intense thirst induces high intake of pure water, which associated with SIADH, usually develops into acute hyponatremia (Hn). As Hn is induced rapidly, experiments to check if Ec acted directly on the Inner Medullary Collecting Ducts (IMCD) of rats were conducted. Rhabdomyolysis and OS were also studied because Ec is known to induce Reactive Oxygen Species (ROS) and tissue damage. To decrease OS, the antioxidant inhibitors N-acetylcysteine (NAC) and Allopurinol (Allo) were used. Methods Rats were maintained on a lithium (Li) diet to block the Vasopressin action before Ec innoculation. AQP2 (Aquaporin 2), ENaC (Epitheliun Sodium Channel) and NKCC2 (Sodium, Potassium, 2 Chloride) expression were determined by Western Blot in isolated IMCDs. The TBARS (thiobarbituric acid reactive substances) and GSH (reduced form of Glutathione) were determined in the Ec group (6 rats injected with Ec-10mg/kg), in Ec+NAC groups (NAC 100mg/Kg/bw i.p.) and in Allo+Ec groups (Allo 50mg/Kg/i.p.). Results Enhanced AQP2 expression revealed that Ec increased water transporter expression, decreased by Li diet, but the expression of the tubular transporters did not change. The Ec, Ec+NAC and Allo+Ec results showed that Ec increased TBARS and decreased GSH, showing evidence of ROS occurrence, which was protected by NAC and Allo. Rhabdomyolysis was only protected by Allo. Conclusion Results showed that Ec induced an increase in AQP2 expression, evidencing another mechanism that might contribute to cause rapid hyponatremia. In addition, they showed that NAC and Allo protected against OS, but only Allo decreased rhabdomyolysis and hyperthermia.
- Lp25 membrane protein from pathogenic Leptospira spp. is associated with rhabdomyolysis and oliguric acute kidney injury in a guinea pig model of leptospirosis(2017) ABREU, Patricia A. E.; SEGURO, Antonio C.; CANALE, Daniele; SILVA, Ana Maria G. da; MATOS, Larissa do R. B.; GOTTI, Tatiane B.; MONARIS, Denize; JESUS, Denise A. de; VASCONCELLOS, Silvio A.; BRITO, Thales de; MAGALDI, Antonio J. B.Acute kidney injury (AKI) from leptospirosis is frequently nonoliguric with hypo- or normokalemia. Higher serum potassium levels are observed in non-survivor patients and may have been caused by more severe AKI, metabolic disarrangement, or rhabdomyolysis. An association between the creatine phosphokinase (CPK) level and maximum serum creatinine level has been observed in these patients, which suggests that rhabdomyolysis contributes to severe AKI and hyperkalemia. LipL32 and Lp25 are conserved proteins in pathogenic strains of Leptospira spp., but these proteins have no known function. This study evaluated the effect of these proteins on renal function in guinea pigs. Lp25 is an outer membrane protein that appears responsible for the development of oliguric AKI associated with hyperkalemia induced by rhabdomyolysis (e.g., elevated CPK, uric acid and serum phosphate). This study is the first characterization of a leptospiral outer membrane protein that is associated with severe manifestations of leptospirosis. Therapeutic methods to attenuate this protein and inhibit rhabdomyolysis-induced AKI could protect animals and patients from severe forms of this disease and decrease mortality.
- MicroRNA Transcriptome Profiling in Heart of Trypanosoma cruzi-Infected Mice: Parasitological and Cardiological Outcomes(2015) NAVARRO, Isabela Cunha; FERREIRA, Frederico Moraes; NAKAYA, Helder I.; BARON, Monique Andrade; VILAR-PEREIRA, Glaucia; PEREIRA, Isabela Resende; SILVA, Ana Maria Goncalves; REAL, Juliana Monte; BRITO, Thales De; CHEVILLARD, Christophe; LANNES-VIEIRA, Joseli; KALIL, Jorge; CUNHA-NETO, Edecio; FERREIRA, Ludmila Rodrigues PintoChagas disease is caused by the parasite Trypanosoma cruzi, and it begins with a short acute phase characterized by high parasitemia followed by a life-long chronic phase with scarce parasitism. Cardiac involvement is the most prominent manifestation, as 30% of infected subjects will develop abnormal ventricular repolarization with myocarditis, fibrosis and cardiomyocyte hypertrophy by undefined mechanisms. Nevertheless, follow-up studies in chagasic patients, as well as studies with murine models, suggest that the intensity of clinical symptoms and pathophysiological events that occur during the acute phase of disease are associated with the severity of cardiac disease observed during the chronic phase. In the present study we investigated the role of microRNAs (miRNAs) in the disease progression in response to T. cruzi infection, as alterations in miRNA levels are known to be associated with many cardiovascular disorders. We screened 641 rodent miRNAs in heart samples of mice during an acute infection with the Colombiana T.cruzi strain and identified multiple miRNAs significantly altered upon infection. Seventeen miRNAs were found significantly deregulated in all three analyzed time points post infection. Among these, six miRNAs had their expression correlated with clinical parameters relevant to the disease, such as parasitemia and maximal heart rate-corrected QT (QTc) interval. Computational analyses identified that the gene targets for these six miRNAs were involved in networks and signaling pathways related to increased ventricular depolarization and repolarization times, important factors for QTc interval prolongation. The data presented here will guide further studies about the contribution of microRNAs to Chagas heart disease pathogenesis.
- Prevalence of celiac disease among blood donors in SAO PAULO - the most populated city in Brazil(2012) ALENCAR, Marilia Lage; ORTIZ-AGOSTINHO, Carmen Lucia; NISHITOKUKADO, Ieda; DAMIAO, Aderson O. M. C.; ABRANTES-LEMOS, Clarice P.; LEITE, Andre Zonetti de Arruda; BRITO, Thales de; CHAMONE, Dalton de Alencar Fischer; SILVA, Maria Elizabeth Rossi da; GIANNELLA-NETO, Daniel; SIPAHI, Aytan MirandaOBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immune-mediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. Sao Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of Sao Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundacao Pro-Sangue Blood Center of Sao Paulo, Sao Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1: 286 among supposedly healthy blood bank volunteers in Sao Paulo, Brazil.
- Human Hemorrhagic Pulmonary Leptospirosis: Pathological Findings and Pathophysiological Correlations(2013) BRITO, Thales De; AIELLO, Vera Demarchi; SILVA, Luis Fernando Ferraz da; SILVA, Ana Maria Goncalves da; SILVA, Wellington Luiz Ferreira da; CASTELLI, Jussara Bianchi; SEGURO, Antonio CarlosBackground: Leptospirosis is a re-emerging zoonosis with protean clinical manifestations. Recently, the importance of pulmonary hemorrhage as a lethal complication of this disease has been recognized. In the present study, five human necropsies of leptospirosis (Weil's syndrome) with extensive pulmonary manifestations were analysed, and the antibodies expressed in blood vessels and cells involved in ion and water transport were used, seeking to better understand the pathophysiology of the lung injury associated with this disease. Principal Findings: Prominent vascular damage was present in the lung microcirculation, with decreased CD34 and preserved aquaporin 1 expression. At the periphery and even inside the extensive areas of edema and intraalveolar hemorrhage, enlarged, apparently hypertrophic type I pneumocytes (PI) were detected and interpreted as a non-specific attempt of clearence of the intraalveolar fluid, in which ionic transport, particularly of sodium, plays a predominant role, as suggested by the apparently increased ENaC and aquaporin 5 expression. Connexin 43 was present in most pneumocytes, and in the cytoplasm of the more preserved endothelial cells. The number of type II pneumocytes (PII) was slightly decreased when compared to normal lungs and those of patients with septicemia from other causes, a fact that may contribute to the progressively low PI count, resulting in deficient restoration after damage to the alveolar epithelial integrity and, consequently, a poor outcome of the pulmonary edema and hemorrhage. Conclusions: Pathogenesis of lung injury in human leptospirosis was discussed, and the possibility of primary non-inflammatory vascular damage was considered, so far of undefinite etiopathogenesis, as the initial pathological manifestation of the disease.
- Pathology and pathogenesis of human leptospirosis: a commented review(2018) BRITO, Thales De; SILVA, Ana Maria Goncalves da; ABREU, Patricia Antonia EstimaLeptospirosis is an acute bacterial septicemic febrile disease caused by pathogenic leptospires, which affect humans and animals in all parts of the world. Transmission can occur by direct contact with infected animals or, more commonly, through indirect contact with water or soil contaminated with urine from infected animals. Leptospires enter the body by penetrating mucous membranes or skin abrasions and disseminate through the hematogenic route. In humans, leptospirosis may cause a wide spectrum of symptoms. Most cases have a biphasic clinical presentation, which begins with the septicemic phase followed by immune manifestations. The severe forms of the disease may be life threatening with multisystem damage including renal failure, hepatic dysfunction, vascular damage, pulmonary hemorrhage and muscle lesions. In this review, we present and discuss the pathogenesis of the human disease and the mechanisms of cell membrane injuries, which occur mainly due to the presence of leptospires and/or their antigen/s in the host tissues.
- Pathology and pathogenesis of human leptospirosis: a commented review (vol 60, e23, 2018)(2018) BRITO, Thales De; SILVA, Ana Maria Goncalves da; ABREU, Patricia Antonia Estima
- Immunohistochemical detection of Lp25 and LipL32 proteins in skeletal and cardiac muscles of fatal human leptospirosis(2020) IGLEZIAS, Silvia D'Andretta; ABREU, Patricia Antonia Estima; KANAMURA, Cristina; MAGALDI, Antonio Jose; SEGURO, Antonio Carlos; BRITO, Thales DeLeptospirosis is an acute infection caused by pathogenic species of the genus Leptospira, which affects humans and animals in all world. In severe forms of the disease, kidneys, liver and lungs are the main affected organs. resulting in acute kidney injury, jaundice and pulmonary hemorrhage. Previous post-mortem studies have shown that lesions are not limited to these organs. Cardiac and striated muscle injuries have already been reported, but the pathophysiology of cardiac and skeletal lesions in leptospirosis is not fully understood. It has been suggested that the tissue damage observed in leptospirosis could be directly mediated by leptospires or by their toxic cellular components. LipL32 and Lp25 are leptospira membrane proteins with unknown functions, that are present only in pathogenic strains of Leptospira spp. Both proteins induce skeletal muscle lesions similar to those observed when normal guinea pigs are inoculated with leptospires. Through immunohistochemistry, this study showed the presence of LipL32 and Lp25 proteins on muscle cell membranes and in the underlying cytoplasm of skeletal muscles, as well as focal lesions in cardiac tissues of fatal cases of leptospirosis. Altogether, these results reinforce that both proteins can be important factors in the pathogenesis of leptospirosis.