ALESSANDRO RODRIGO BELON
Projetos de Pesquisa
Unidades Organizacionais
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
8 resultados
Resultados de Busca
Agora exibindo 1 - 8 de 8
- A simplified experimental model of large-for-size liver transplantation in pigs(2013) LEAL, Antonio Jose Goncalves; TANNURI, Ana Cristina Aoun; BELON, Alessandro Rodrigo; GUIMARAES, Raimundo Renato Nunes; COELHO, Maria Cecilia Mendonca; GONCALVES, Josiane de Oliveira; SOKOL, Suellen Serafini; MELO, Evandro Sobroza De; OTOCH, Jose Pinhata; TANNURI, UenisOBJECTIVE: The ideal ratio between liver graft mass and recipient body weight for liver transplantation in small infants is unknown; however, if this ratio is over 4%, a condition called large-for-size may occur. Experimental models of large-for-size liver transplants have not been described in the literature. In addition, orthotopic liver transplantation is marked by high morbidity and mortality rates in animals due to the clamping of the venous splanchnic system. Therefore, the objective of this study was to create a porcine model of large-for-size liver transplantation with clamping of the supraceliac aorta during the anhepatic phase as an alternative to venovenous bypass. METHOD: Fourteen pigs underwent liver transplantation with whole-liver grafts without venovenous bypass and were divided into two experimental groups: the control group, in which the weights of the donors were similar to the weights of the recipients; and the large-for-size group, in which the weights of the donors were nearly 2 times the weights of the recipients. Hemodynamic data, the results of serum biochemical analyses and histological examination of the transplanted livers were collected. RESULTS: The mortality rate in both groups was 16.5% (1/7). The animals in the large-for-size group had increased serum levels of potassium, sodium, aspartate aminotransferase and alanine aminotransferase after graft reperfusion. The histological analyses revealed that there were no significant differences between the groups. CONCLUSION: This transplant method is a feasible experimental model of large-for-size liver transplantation.
- Experimental rnodel of intracranial hypertension with continuous multiparametric monitoring in swine(2013) ANDRADE, Almir Ferreira de; SOARES, Matheus Schmidt; PATRIOTA, Gustavo Cartaxo; BELON, Alessandro Rodrigo; PAIVA, Wellingson Silva; BOR-SENG-SHU, Edson; OLIVEIRA, Marcelo de Lima; NASCIMENTO, Clarissa Nobrega; NOLETO, Gustavo Sousa; ALVES JUNIOR, Aderaldo Costa; FIGUEIREDO, Eberval Gadelha; OTOCH, Jose Pinhata; TEIXEIRA, Manoel JacobsenObjective: Intracranial hypertension (IN) develops in approximately 50% of all patients with severe traumatic brain injury (TBI). Therefore, it is very important to identify a suitable animal model to study and understand the pathophysiology of refractory IH to develop effective treatments. Methods: We describe a new experimental porcine model designed to simulate expansive brain hematoma causing IH. Under anesthesia, was simulated with a balloon insufflation. The IH variables were measured with intracranial pressure (ICP) parenchymal monitoring, epidural, cerebral oximetry, and transcranial Doppler (TCD). Results: None of the animals died during the experiment. The ICP epidural showed a slower rise compared with parenchymal ICP. We found a correlation between ICP and cerebral oximetry. Conclusion: The model described here seems useful to understand some of the pathophysiological characteristics of acute IH.
- Evaluation of the Maintained Effect of 3% Hypertonic Saline Solution in an Animal Model of Intracranial Hypertension(2016) SOUSA JR., Leonardo M.; ANDRADE, Almir F. de; BELON, Alessandro R.; SOARES, Matheus S.; AMORIM, Robson Luis; OTOCHI, Jose Pinhata; TEIXEIRA, Manoel J.; PAIVA, Wellingson S.Background: Current clinical treatment methods for refractory intracranial hypertension include elevation of the decubitus, ventilation adjustment, and use of hypertonic solutions such as hypertonic saline and mannitol solutions. Previous studies have shown that hypertonic solutions are particularly effective. Although several concentrations of saline solution have been proposed, a 3% solution is the most widely used. The aim of this study was to evaluate the maintained efficacy of a 3% hypertonic saline solution in an experimental model of intracranial hypertension. Material/Methods: A porcine model of reversible intracranial hypertension was created by inserting a balloon catheter into the brain parenchyma, which was inflated and deflated to simulate intracranial hypertension and its surgical correction. The experiment included 3 groups of animals (A, B, and C) with different balloon inflation volumes. In group B, balloons were inflated 2 times to simulate reexpansion. A 20 mL/kg bolus of 3% saline solution was infused using a pump 90 minutes after the start of balloon inflation, and the effects of intracranial pressure were evaluated 60 minutes after infusion. Results: No increases outside of the normal range were observed in mean serum sodium concentrations (p=0.09). In addition, we identified no differences within each group in serum sodium levels measured during hypertonic saline infusion (p=0.21). No significant reductions in intracranial pressure were observed in any of the 3 groups. Conclusions: Bolus infusion of 3% hypertonic saline solution with the aid of a pump does not significantly reduce intracranial pressure in an animal model of intracranial hypertension.
conferenceObject CORRELATION BETWEEN INTRACRANIAL PRESSURE AND MEASUREMENT OF OPTIC NERVE SHEATH IN A SWINE MODEL OF INTRACRANIAL HYPERTENSION(2014) JEMG, Robson Luis Amorim Brasil Ping; ANDRADE, Almir Ferreira de; PAIVA, Wellingson Silva; BELON, Alessandro R.; OLIVEIRA, Marcelo Lima de; AZEVEDO, Maira; BOR-SENG-SHU, Edson; FIGUEIREDO, Eberval Gadelha; OTOCH, Jose Pinhata; TEIXEIRA, Manoel JacobsenconferenceObject CORRELATION BETWEEN INTRACRANIAL PRESSURE AND MEASUREMENT OF OPTIC NERVE SHEATH IN A SWINE MODEL OF INTRACRANIAL HYPERTENSION(2014) JEMG, Robson Luis Amorim Brasil Ping; ANDRADE, Almir Ferreira de; PAIVA, Wellingson Silva; BELON, Alessandro R.; OLIVEIRA, Marcelo Lima de; AZEVEDO, Maira; BOR-SENG-SHU, Edson; FIGUEIREDO, Eberval Gadelha; OTOCH, Jose Pinhata; TEIXEIRA, Manoel Jacobsen- A NEW MODEL OF LARGE-FOR-SIZE PORCINE LIVER TRANSPLANTATION WITH AORTIC CLAMPING(2013) LEAL, Antonio Jose Goncalves; BELON, Alessandro Rodrigo; TANNURI, Ana Cristina Aoun; GUIMARAES, Raimundo Renato Nunes; COELHO, Maria Cecilia Mendonca; GONCALVES, Josiane De Oliveira; SOKOL, Suellen Serafini; MELO, Evandro Sobroza De; OTOCH, Jose Pinhata; TANNURI, UenisOBJECTIVE: The objective of the present study was to create a swine model of large-for-size liver transplantation, without venovenous bypass but clamping of the supraceliac aorta during the hepatic phase. MATERIAL AND METHODS: Fourteen Landrace-Large white pigs (weight 17 to 20 kg) were anesthetized with continuous infusion of propofol and fentanyl, and mechanically ventilated. They underwent orthotopic liver transplantation(OLT) with whole liver grafts and were divided randomly into two experimental groups, according to donor size. Regular size group (NS-n=7): donors weight were similar to the receptors (17–20 kg). Large-for-size group (LFS-n=7): donors weight was nearly two times the receptor ′ s (40–50 kg). Blood for serum levels of aspartate aminotransferase (AST) and hepatic tissue for histological examination and quantification of Bax (a proapoptotic protein) gene expression though real time PCR were sampled from the recipient at baseline, 1 and 3 h after portal reperfusion. RESULTS: In NS group, one death was related to hemodynamic instability just after aortic release and another due to bleeding by laceration on graft surface. In LFS 1,3 group, the two deaths were associated to hemodynamic instability just after aortic release. Table 1 shows the changes in AST levels over the experiment in both groups. Table 2 presents the histological results. Table 3 shows the results of Bax gene expression for the NS and LFS groups. CONCLUSION: This large-animal model is straightforward, reproducible, and clinically relevant. It provides the appropriate size and anatomy that resemble humans for the development and practice of new surgical techniques.
conferenceObject INTRACRANIAL HYPERTENSION MODEL IN PIGS: ASSESSMENT WITH TRANSCRANIAL DOPPLER AND INTRACRANIAL PRESSURE MONITORING(2014) ANDRADE, Almir Ferreira de; MATHEUS, S.; PATRIOTA, Gustavo C.; BELON, Alessandro; PAIVA, Wellingson S.; JENG, Brasil P.; BOR-SENG-SHU, Edson; OLIVEIRA, Marcelo; NASCIMENTO, Clarissa; AMORIM, Robson; FIGUEIREDO, Eberval G.; OTOCH, Jose P.; TEIXEIRA, Manoel J.- Post-COVID-19 condition: systemic inflammation and low functional exercise capacity(2024) CASTRO, Gabriela Salim de; GAMA, Leonardo R.; RAMOS, Alexandre Ferreira; SILVA, Guilherme Gatti da; TEIXEIRA, Alexandre Abilio de Souza; CUNHA-NETO, Edecio; SOUZA, Heraldo Possolo de; MARIE, Suely K.; TALIB, Leda L.; COELHO, Veronica; KALIL, Jorge; ARAUJO, Adriana Ladeira de; RITTO, Ana Paula; BELON, Alessandro Rodrigo; SANTOS, Amanda Soares; BARRERE, Ana Paula Noronha; SAWAMURA, Marcio V. Y.; LAMAS, Celina Almeida; BALDI, Bruno Guedes; CARVALHO, Carlos R. R.; KULIKOWSKI, Leslie Domenici; DAMIANO, Rodolfo Furlan; IMAMURA, Marta; ROSA NETO, Jose Cesar; LIRA, Fabio S.; OTOCH, Jose Pinhata; MIGUEL, Euripedes Constantino; BATTISTELLA, Linamara; FORLENZA, Orestes V.; BUSATTO, Geraldo; SEELAENDER, MariliaIntroduction Post-COVID-19 condition (PCC) is characterised by a plethora of symptoms, with fatigue appearing as the most frequently reported. The alterations that drive both the persistent and post-acute disease newly acquired symptoms are not yet fully described. Given the lack of robust knowledge regarding the mechanisms of PCC we have examined the impact of inflammation in PCC, by evaluating serum cytokine profile and its potential involvement in inducing the different symptoms reported.Methods In this cross-sectional study, we recruited 227 participants who were hospitalised with acute COVID-19 in 2020 and came back for a follow-up assessment 6-12 months after hospital discharge. The participants were enrolled in two symptomatic groups: Self-Reported Symptoms group (SR, n = 96), who did not present major organ lesions, yet reported several debilitating symptoms such as fatigue, muscle weakness, and persistent loss of sense of smell and taste; and the Self-Reported Symptoms and decreased Pulmonary Function group (SRPF, n = 54), composed by individuals with the same symptoms described by SR, plus diagnosed pulmonary lesions. A Control group (n = 77), with participants with minor complaints following acute COVID-19, was also included in the study. Serum cytokine levels, symptom questionnaires, physical performance tests and general clinical data were obtained in the follow-up assessment.Results SRPF presented lower IL-4 concentration compared with Control (q = 0.0018) and with SR (q = 0.030), and lower IFN-alpha 2 serum content compared with Control (q = 0.007). In addition, SRPF presented higher MIP-1 beta serum concentration compared with SR (q = 0.029). SR presented lower CCL11 (q = 0.012 and q = 0.001, respectively) and MCP-1 levels (q = 0.052 for both) compared with Control and SRPF. SRPF presented lower G-CSF compared to Control (q = 0.014). Female participants in SR showed lower handgrip strength in relation to SRPF (q = 0.0082). Male participants in SR and SRPF needed more time to complete the timed up-and-go test, as compared with men in the Control group (q = 0.0302 and q = 0.0078, respectively). Our results indicate that different PCC symptom profiles are accompanied by distinct inflammatory markers in the circulation. Of particular concern are the lower muscle function findings, with likely long-lasting consequences for health and quality of life, found for both PCC phenotypes.