ALESSANDRO RODRIGO BELON
Projetos de Pesquisa
Unidades Organizacionais
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- Estimation of intracranial pressure by ultrasound of the optic nerve sheath in an animal model of intracranial hypertension(2021) JENG, Brasil Chian Ping; ANDRADE, Almir Ferreira de; BRASIL, Sergio; BOR-SENG-SHU, Edson; BELON, Alessandro Rodrigo; ROBERTIS, Maira; DE-LIMA-OLIVEIRA, Marcelo; RUBIANO, Andres Mariano; GODOY, Daniel Agustin; TEIXEIRA, Manoel Jacobsen; PAIVA, Wellingson SilvaBackground: Ultrasound of the optic nerve sheath diameter (ONSD) has been used as a non-invasive and cost-effective bedside alternative to invasive intracranial pressure (ICP) monitoring. However, ONSD time-lapse behavior in intracranial hypertension (ICH) and its relief by means of either saline infusion or surgery are still unknown. The objective of this study was to correlate intracranial pressure (ICP) and ultrasonography of the optic nerve sheath (ONS) in an experimental animal model of ICH and deter-mine the interval needed for ONSD to return to baseline levels. Methods: An experimental study was conducted on 30 pigs. ONSD was evaluated by ultrasound at differ-ent ICPs generated by intracranial balloon inflation, saline infusion, and balloon deflation, and measured using an intraventricular catheter. Results: All variables obtained by ONS ultrasonography such as left, right, and average ONSD (AON) were statistically significant to estimate the ICP value. ONSD changed immediately after balloon inflation and returned to baseline after an average delay of 30 min after balloon deflation (p = 0.016). No statistical sig-nificance was observed in the ICP and ONSD values with hypertonic saline infusion. In this swine model, ICP and ONSD showed linear correlation and ICP could be estimated using the formula:-80.5 + 238.2 x AON. Conclusion: In the present study, ultrasound to measure ONSD showed a linear correlation with ICP, although a short delay in returning to baseline levels was observed in the case of sudden ICH relief.
- Inflammatory markers assessment in an animal model of intracranial hypertension: a randomized trial(2021) SANTO, Marcelo Prudente do Espirito; FARIA, Caroline Silverio; SOLLA, Davi Jorge Fontoura; PIPEK, Leonardo Zumerkorn; BELON, Alessandro Rodrigo; JENG, Brasil Ping; ANDRADE, Almir Ferreira de; TEIXEIRA, Manoel Jacobsen; PAIVA, Wellingson SilvaBackground: Intracranial hypertension (ICH) is a common final pathway of most neurosurgical pathologies and leads to poor prognosis if not detected and treated properly. Inflammatory markers have been assessed in clinical scenarios of neurological injuries, in which systemic and brain tissue aggressions may introduce bias. There is a lack of studies under controlled settings to isolate the ICH effect on inflammation. This study aims to evaluate the effects of ICH on the serum concentration of cytokines as biomarkers of neuroinflammation in an experimental model which isolates ICH from potential confounding variables. Methods: An established model of ICH using an intracerebral pediatric bladder catheter and a multisensor intraparenchymal catheter was used in adult pigs (Sus domesticus). The animals were randomly allocated to 2 groups based on the catheter balloon volume used to simulate the ICP increase (4 ml or 7 ml). Cytokines were measured in 4 timepoints during the experiment: (1) 15 min before balloon insufflation; (2) 5 min after insufflation; (3) 125 min after insufflation; (4) 60 min after deflation. The following cytokines were measured IL-1 alpha; IL-1 beta; IL-1ra; IL-2; IL-4; IL-6; IL-8; IL-10; IL-12; IL-18; TNFa. Generalized estimating equations were modeled to compare the ICP and cytokines values between the groups along the experiment. The study sample size was powered to detect interactions between the groups and the study moments with an effect size (f) of at least 0.3. The ARRIVE checklist was followed. Results: A total of 20 animals were studied (10 in each group, 4 ml or 7 ml balloon volume insufflation). The animal model was successful in increasing the ICP along the moments of the experiment (p < 0,001) and in creating an ICP gradient between the groups (p = 0,004). The interaction term (moment x group) was also significant (p < 0,001). There was a significant association between ICP elevation and most cytokines variation. The cytokines IL-1 alpha, IL-1 beta, IL1-ra, IL-6, IL-12, and IL-18 increased, whereas IL-2, IL-4, and TNF-alpha decreased. IL-10 did not vary significantly in response to the ICP elevation. Conclusion: The serum concentration of cytokines varied in response to intracranial hypertension. The study demonstrated the specific changes in each cytokine afterintracranial hypertension and provides key information to guide neuroinflammation clinical research. The proposed experiment was successful as an animal model to the study of neuroinflammation biomarkers.