LUIZ FERNANDO FERRAZ DA SILVA
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina - Docente
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
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conferenceObject BRAIN DEATH PARADOXICALLY INDUCES LEUCOPENIA AND REDUCTION IN THE NUMBER OF BONE MARROW CELLS(2013) MENEGAT, Laura; BORELLI, Primavera; SIMAS, Rafael; CALIMAN, Julia Maria; SILVA, Luiz Fernando Ferraz; MOREIRA, Luiz Felipe; SANNOMIYA, Paulina- Indications and Limitations of Fine Needle Aspiration Biopsy of Lateral Cervical Masses(2012) CARNEIRO, Paulo Campos; SILVA, Luiz Fernando Ferraz da
- Sex-related differences in lung inflammation after brain death(2016) BREITHAUPT-FALOPPA, Ana Cristina; FERREIRA, Sueli G.; KUDO, Guilherme K.; ARMSTRONG JR., Roberto; TAVARES-DE-LIMA, Wothan; SILVA, Luiz Fernando Ferraz da; SANNOMIYA, Paulina; MOREIRA, Luiz Felipe P.Background: Donor sex has been suggested to be a factor influencing organ transplantation outcome. Sex hormones possess inflammatory and immune-mediating properties; therefore, immune responses may differ between males and females. Brain death (BD) affects organ function by numerous mechanisms including alterations in hemodynamics, hormonal changes, and increased systemic inflammation. In this study, we investigated sex-dependent differences in the evolution of lung inflammation in a rat model of BD. Materials and methods: BD was induced by a sudden increase in intracranial pressure by rapidly inflating a balloon catheter inserted into the intracranial space. Groups of male, female, and ovariectomized (OVx) female rats were used. Lung vascular permeability, inducible nitric oxide synthase, and intercellular adhesion molecule 1 expression were analyzed 6 h after BD. Serum female sex hormones, vascular endothelial growth factor, and cytokine-induced neutrophil chemoattractant 1 levels were also quantified. Lung sections were analyzed by histology. Results: After 6 h of BD, serum estradiol and progesterone concentrations in female rats were significantly reduced. Lung microvascular permeability was increased in females compared to males. Cytokine-induced neutrophil chemoattractant 1 and vascular endothelial growth factor concentrations were increased in female rats compared to males. Furthermore, female rats showed higher levels of leukocyte infiltration and inducible nitric oxide synthase expression in the lung parenchyma. Conclusions: Our results indicate that the more severe lung inflammation in female animals after BD might be related to acute estradiol reduction. Based on our findings, we believe that, in a future study, a group of female treated with estradiol after BD could indicate a possible therapy for the control of lung inflammation in the female donor.
- Left Common Carotid Artery Biomechanical Properties in Individuals over 80 years: Women Have Stiffer Vessels(2020) GOMES, Vivian Carla; SILVA, Luiz Fernando da; ZYNGIER, Selene Perrotti; SILVESTRE, Gina Camillo; QUEIROZ, Alexandre; MARQUES, Michele Alberto; SILVA, Erasmo Simao daBackground: Considering the longevity of the worldwide population, the cardiovascular diseases deserve particular attention, especially the carotid artery disease in the >= 80-year-old population. The stiffness of the common carotid artery, for example, has been showed in numerous clinical studies as a marker of increased risk of stroke, dementia, and depression. Besides, with the emergence of new surgical techniques such as the transcarotid artery revascularization that uses the common carotid artery as a workstation, the biomechanical and histological features of this vessel, more than ever, must be detailed. Methods: Left common carotid artery fragments from 9 cadaver donors (>= 80 years old) were evaluated. Biomechanical (failure stress, tension, and strain) and histological (percentage of collagen and elastic fibers) features of these samples were analyzed with special focus on gender differences. Results: Statistically significant differences in biomechanical and histological features between the genders were observed. The percentage of collagen fiber in intima (P = 0.008) and media (P = 0.041) layers was significantly lower in men than in women. A higher elasticity (failure strain) of the specimens in male gender was also observed (P = 0.025). No significant difference was observed in the layers thickness between the genders regardless which part of the arterial wall was considered. Conclusions: These biomechanical and histological findings could be the responsible for the higher left common carotid artery stiffness observed among >80-year-old women when compared with men in numerous clinical studies in literature.
conferenceObject High Prevalence of Myocardial Fibrosis in Patients After Heart Transplantation(2015) SILVA FILHO, M. R.; SETUGUTI, D. T.; CARVALHO, V. O.; BENVENUTI, L. A.; SILVA, L. F.; BOCCHI, E. A.- Aorta Rupture Assay: Comparing the Failure Pressure of Infrarenal Abdominal Aortic Aneurysm and Normal Abdominal Aorta Specimens(2019) GOMES, Vivian C.; RAGHAVAN, Madhavan L.; SILVA, Luiz F. da; ZYNGIER, Selene; SILVESTRE, Gina; QUEIROZ, Alexandre; MARQUES, Michele A.; SILVA, Erasmo S. da
- Sex differences on solid organ histological characteristics after brain death(2016) SIMAO, Raif Restivo; FERREIRA, Sueli Gomes; KUDO, Guilherme Konishi; ARMSTRONG JUNIOR, Roberto; SILVA, Luiz Fernando Ferraz da; SANNOMIYA, Paulina; BREITHAUPT-FALOPPA, Ana Cristina; MOREIRA, Luiz Felipe PinhoPURPOSE: To investigate gender differences in the evolution of the inflammatory process in rats subjected to brain death (BD). METHODS: Adult Wistar rats were divided into three groups: female; ovariectomized female; and male rats. BD was induced using intracranial balloon inflation and confirmed by maximal pupil dilatation, apnea, absence of reflex, and drop of mean arterial pressure. Six hours after BD, histological evaluation was performed in lungs, heart, liver and kidneys, and levels of inflammatory proteins, estrogen, progesterone, and corticosterone were determined in plasma. RESULTS: In the lungs, females presented more leukocyte infiltration compared to males (p<0.01). Ovariectomized female rat lungs were more hemorrhagic compared to other groups (p<0.001). In the heart, females had higher leukocyte infiltration and tissue edema compared to males (p<0.05). In the liver and kidneys, there were no differences among groups. In female group estradiol and progesterone were sharply reduced 6 hours after BD (p<0.001) to values observed in ovariectomized females and males. Corticosterone levels were similar. CONCLUSIONS: Sex hormones influence the development of inflammation and the status of organs. The increased inflammation in lungs and heart of female rats might be associated with the acute reduction in female hormones triggered by BD.
article 12 Citação(ões) na Scopus Collagen Type I, Collagen Type III, and Versican in Vocal Fold Lamina Propria(2011) BUEHLER, Rogerio B.; SENNES, Luiz U.; TSUJI, Domingos H.; MAUAD, Thais; SILVA, Luiz Ferraz da; SALDIVA, Paulo N.Objective: To analyze the distributions of collagen type I, collagen type III, and versican in the lamina propria of the human vocal fold. Design: Cross-sectional analysis of cadaveric vocal folds of adult human larynges. Setting: Academic tertiary referral center. Subjects: Larynges harvested at autopsy from 10 adult men and 10 adult women. Main Outcome Measures: Immunohistochemical reactions were performed using antihuman monoclonal antibodies to analyze the expression of collagen type I, collagen type III, and versican. Results: Collagen type I density was lower in the intermediate layer compared with the superficial and deep layers of vocal folds. Collagen type III density was lower in the intermediate layer compared with the deep layer. Versican density was lower in the superficial layer compared with the intermediate and deep layers. Versican density was lower in the lamina propria of women compared with men; this difference was noted in the superficial layer only. There was a positive correlation between collagen type III and versican densities within the lamina propria. Conclusion: Collagen type I, collagen type III, and versican are distributed differently within the lamina propria layers of the adult vocal folds.- Effects of selective bile duct ligation on liver parenchyma in young animals: histologic and molecular evaluations(2012) TANNURI, Ana Cristina A.; COELHO, Maria Cecilia M.; GONCALVES, Josiane de Oliveira; SANTOS, Maria Merces; SILVA, Luiz Fernando Ferraz da; BENDIT, Israel; TANNURI, UenisBackground/Purpose: The mechanisms of increased collagen production and liver parenchyma fibrosis are poorly understood. These phenomena are observed mainly in children with biliary obstruction (BO), and in a great number of patients, the evolution to biliary cirrhosis and hepatic failure leads to the need for liver transplantation before adolescence. However, pediatric liver transplantation presents with biliary complications in 20% to 30% of cases in the postoperative period. Intra-or extrahepatic stenosis of bile ducts is frequent and may lead to secondary biliary cirrhosis and the need for retransplantation. It is unknown whether biliary stenosis involving isolated segments or lobes may affect the adjacent nonobstructed lobes by paracrine or endocrine means, leading to fibrosis in this parenchyma. Therefore, the present study aimed to create an experimental model of selective biliary duct ligation in young animals with a subsequent evaluation of the histologic and molecular alterations in liver parenchyma of the obstructed and nonobstructed lobes. Methods: After a pilot study to standardize the surgical procedures, weaning rats underwent ligation of the bile ducts of the median, left lateral, and caudate liver lobes. The bile duct of the right lateral lobe was kept intact. To avoid intrahepatic biliary duct collaterals neoformation, the parenchymal connection between the right lateral and median lobes was clamped. The animals were divided into groups according to the time of death: 1, 2, 3, 4, and 8 weeks after surgical procedure. After death, the median and left lateral lobes (with BO) and the right lateral lobe (without BO [NBO]) were harvested separately. A group of 8 healthy nonoperated on animals served as controls. Liver tissues were subjected to histologic evaluation and quantification of the ductular proliferation and of the portal fibrosis. The expressions of smooth muscle alpha-actin (alpha-SMA), desmin, and transforming growth factor beta 1 genes were studied by molecular analyses (semiquantitative reverse transcriptase-polymerase chain reaction and real-time polymerase chain reaction, a quantitative method). Results: Histologic analyses revealed the occurrence of ductular proliferation and collagen formation in the portal spaces of both BO and NBO lobes. These phenomena were observed later in NBO than BO. Bile duct density significantly increased 1 week after duct ligation; it decreased after 2 and 3 weeks and then increased again after 4 and 8 weeks in both BO and NBO lobes. The portal space collagen area increased after 2 weeks in both BO and NBO lobes. After 3 weeks, collagen deposition in BO was even higher, and in NBO, the collagen area started decreasing after 2 weeks. Molecular analyses revealed increased expression of the alpha-SMA gene in both BO and NBO lobes. The semiquantitative and quantitative methods showed concordant results. Conclusions: The ligation of a duct responsible for biliary drainage of the liver lobe promoted alterations in the parenchyma and in the adjacent nonobstructed parenchyma by paracrine and/or endocrine means. This was supported by histologic findings and increased expression of alpha-SMA, a protein related to hepatic fibrogenesis.
- Experimental Study of Rupture Pressure and Elasticity of Abdominal Aortic Aneurysms Found at Autopsy(2021) GOMES, Vivian Carla; RAGHAVAN, Madhavan Lakshmi; SILVA, Luiz Fernando Ferraz da; GOMES, Jorge; SILVESTRE, Gina Camillo; QUEIROZ, Alexandre; MARQUES, Michele Alberto; ZYNGIER, Selene Perrotti; CHUNG, Timothy Kwang-Joon; SILVA, Erasmo Simao daBackground: Resistance and elasticity of normal and aneurysmal aorta walls are directly associated with this vessel's growth and rupture. This study aims to experimentally analyze the biomechanical behavior of aneurysmal specimens found at autopsy, comparing them with normal diameter aortas removed from age-matched donors. Methods: Thirty-eight human aortas (30 normal aortas; 8 infrarenal abdominal aortic aneurysms) were harvested during autopsy. An apparatus was built with a digital gauge, plastic tray, connections, and hoses that conducted fluid (air) from a pump through the system. Specimens were dissected, and a flexible balloon was introduced in each of them to avoid leakage. The specimens were fastened on the test tray, and activation of the air pump enhanced system pressure up to their rupture. Results: All 8 aneurysms and all 30 normal aortas specimens evolved to rupture under inflation pressures above 590 mm Hg (mean +/- standard deviation = 1,035 +/- 375 mm Hg) and 840 mm Hg (mean +/- SD = 1,405 +/- 342 mm Hg), respectively. In the aneurysm group, 25% of specimens did not rupture in their most dilated region. Percentage of increment in diameter was higher in normal aortas (mean +/- SD = 0.2106 +/- 0.144) than in aneurysms (mean +/- SD = 0.093 +/- 0.070). Conclusions: In the present experiment, unruptured infrarenal abdominal aortic aneurysms could support high pressures nearly as much as nonaneurysmal abdominal aortas. In some specimens, the most dilated part of the aneurysm was not the most vulnerable under pressure. Normal aortas presented higher elasticity than aneurysms.