SUELLEN SERAFINI
Projetos de Pesquisa
Unidades Organizacionais
LIM/30 - Laboratório de Investigação em Cirurgia Pediát, Hospital das Clínicas, Faculdade de Medicina
7 resultados
Resultados de Busca
Agora exibindo 1 - 7 de 7
- 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.
- Sepsis and cirrhosis in growing animals: description of a new experimental model and its pathological and immunological reliability(2020) MORAES, Pedro Augusto Dantas de; TANNURI, Ana Cristina Aoun; RIOS, Livio Moreira; PEES, Vitor Ribeiro; GONCALVES, Josiane de Oliveira; SERAFINI, Suellen; TANNURI, UenisOBJECTIVES: In cirrhotic children, infection events and sepsis are more frequent and more severe due to immune dysfunction. The objectives of the current study were therefore to develop an experimental model of infection and sepsis in cirrhotic weaning growing rats, by the use of bile duct ligation (BDL) and cecal ligation and puncture (CLP). Additionally, the correlation of the clinico-histopathological data and serial cytokine levels in septic cirrhotic and non-cirrhotic animals was studied. METHODS: Young Wistar rats of age 21 days and of weight between 70-90 g were divided into 12 groups according to the surgical procedure performed: sham (sacrificed after 2 or 4 weeks), BDL (sacrificed after 2 or 4 weeks), CLP (2- or 4-week old animals sacrificed after 12 or 24 hours), BDL+CLP (2- or 4-week old animals sacrificed after 12 hours). Histopathological studies and determination of serum levels of cytokines IL-1 beta, IL10, and TNF-alpha, for studies of systemic infection, were performed. Murine sepsis scores (MSS) based on the clinical aspects just before euthanasia were also included. RESULTS: A transitory increase in IL-1, IL-10, and TNF-alpha levels was observed, with different patterns according to the groups. Two-hit groups tended to present with higher values of serum cytokines and histopathological scores than their septic non-cirrhotic counterparts. There was a correlation between mortality rate and MSS (p<0.0001). CONCLUSION: The model is feasible and may be utilized in studies on liver cirrhosis and infection in growing animals.
- Are there differences in the growth adaptation processes of growing and mature organism models of short bowel syndrome?(2018) TANNURI, Ana Cristina Aoun; ROTONDO, Italo Geraldo; BARROS, Guilherme Garcia; VAISBERG, Victor Van; MENDES-NETO, Cicero; PAES, Vitor Ribeiro; COELHO, Maria Cecilia Mendonca; GONCALVES, Josiane; SERAFINI, Suellen; TANNURI, UenisOBJECTIVES: The purpose of this study was to present an experimental model of short bowel syndrome (SBS) in weaning rats and to compare the adaptative mechanisms of the remaining bowel in weaning rats and adult animals by means of morphometric, histologic and molecular methods. METHODS: Twenty-four weaning rats were divided into 3 groups of 8 animals, one control group and two short bowel groups (euthanasia after 4 and 21 days), and were compared with similar adult groups. Morphometric evaluations of the animals and histopathological and molecular studies of the remaining bowel were performed. RESULTS: The weight of young rats increased after enterectomy, whereas that of adult rats decreased after enterectomy (p < 0.0001). The ratio of intestinal length/body weight was significantly higher in weaning rats than in adults (p < 0.002), showing that intestinal growth was more intense in weaning rats. Intestinal resection promoted increased thickness of the small bowel lamina propria (p=0.001) and reduced thickness of the colon lamina propria (p=0.04) in weaning rats relative to those in adults. In addition, intestinal resection promoted increased expression of the Bcl-xl gene (antiapoptotic) in adult animals compared with that in weaning rats (p=0.001). CONCLUSION: Morphometric, histological and molecular differences were shown in the adaptation processes of growing and mature organisms.
- Wound healing in weaning, adult, and old rats with provoked incisional hernias. A comparative study(2022) AMARAL, Raphael Nogueira do; TANNURI, Ana Cristina Aoun; NERI, Junia Marielle Teixeira Rodrigues; REIS, Hugo de Souza; GONCALVES, Josiane Oliveira; SERA, Suellen; TANNURI, UenisBackground: Incisional hernias are more frequent in adults than in children. It is hypothesized that a more efficient healing process in pediatric patients could explain this difference in incidence. Certain elements of healing such as neovascularization, degree of inflammation, percentage of mature and immature collagen, the proliferation of fibroblasts, and expression of certain genes could explain why healing in children is more efficient when com-pared to the adult and elderly populations. Materials and methods: Seventy-one rats of 3 different age groups (weaning, adult, and old) underwent surgery with 3 different incisions (vertical, oblique, and horizontal). During the procedure, the skin and abdominal wall of the animal were sectioned and only the skin was sutured to mimic incisional hernia in the animals. Four weeks after surgery, the rats were euthanized, their skin was removed, and the extent of scar tissue formed in the muscle opening was measured. In addition, samples of the scar tissue were collected for histological, immunohistochemical, and molecular analyzes. Nine rats served as controls. Results: Shorter-length hernias were formed in weaning rats when compared to old ones when the surgical incision was horizontal (p = 0.03). There was a greater proliferation of fibroblasts in rats in the younger age groups, regardless of the type of incision. The Lox gene was more expressed in weaning rats with vertical and oblique incisions. Conclusions: These differences could explain the better healing and lower incidence of hernias in the pediatric population, although this aspect requires further studies.
- Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation(2015) LEAL, Antonio Jose Goncalves; TANNURI, Ana Cristina Aoun; BELON, Alessandro Rodrigo; GUIMARAES, Raimundo Renato Nunes; COELHO, Maria Cecilia Mendonca; GONCALVES, Josiane de Oliveira; SERAFINI, Suellen; MELO, Evandro Sobroza de; TANNURI, UenisOBJECTIVE: In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity. METHODS: Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax ( pro-apoptotic), Bcl-XL (anti-apoptotic), c-Fos and c-Jun (immediate-early genes), ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration), intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning) and TGF-beta (a pro-fibrogenic cytokine). RESULTS: All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression. CONCLUSION: Ischemia-reperfusion injury in this model of large-for-size liver transplantation could be partially attenuated by ischemic preconditioning.
- A new systematization of histological analysis for the diagnosis of Hirschsprung's disease(2023) SERAFINI, Suellen; SANTOS, Maria Merces; TANNURI, Ana Cristina Aoun; LORETO, Celso Di; GONCALVES, Josiane de Oliveira; TANNURI, UenisBackground: Hirschsprung's Disease (HD) is characterized by intestinal sub-occlusion and the absence of enteric ganglion cells. A rectal biopsy examination is performed to confirm the diagnosis. In a recent study, we demon-strated that the analysis of 60 sections of rectal mucosa and submucosa stained by H&E may ensure a 90% diag-nostic accuracy. Although the need to analyze so many sections makes the process of reading the slides more time-consuming, this encouraged us to study their distribution in the healthy rectal submucosa, to simplify the diagnosis.Objectives: To develop a method that facilitates HD diagnosis by studying the distribution of ganglion cells in the submucosal plexus. Methods: Using the calretinin technique, we studied the distribution of plexuses in 60 fragments of rectal submu-cosa from 19 cadavers. After the study, the reading method created was used for diagnosis in 47 cases of suspected HD, using H&E staining. The accuracy was verified by comparing the results obtained with H&E to those obtained with the acetylcholinesterase technique, the golden standard in our laboratory.Results: The study of submucosal plexus distribution showed that just by examining the submucosal region every 20 mu m, approximately, it is possible to locate a ganglionic plexus, and we have already been able to diagnose HD with 93% accuracy. Conclusion: The study of ganglion cell distribution enabled the creation of a simplified method for reading the slides. The method applied achieved good accuracy and it can be used as an alternative method in HD diagnosis.
- Immediate expression of c-fos and c-jun mRNA in a model of intestinal autotransplantation and ischemia-reperfusion in situ(2015) SANTOS, Maria Mercês; TANNURI, Ana Cristina Aoun; COELHO, Maria Cecilia Mendonça; GONÇALVES, Josiane de Oliveira; SERAFINI, Suellen; SILVA, Luiz Fernando Ferraz da; TANNURI, UenisOBJECTIVE: Intestinal ischemia-reperfusion injury occurs in several clinical conditions and after intestinal transplantation. The aim of the present study was to investigate the phenomena of apoptosis and cell proliferation in a previously described intestinal ischemia-reperfusion injury autograft model using immunohistochemical markers. The molecular mechanisms involved in ischemia-reperfusion injury repair were also investigated by measuring the expression of the early activation genes c-fos and c-jun, which induce apoptosis and cell proliferation. MATERIALS AND METHODS: Thirty adult male Wistar rats were subjected to surgery for a previously described ischemia-reperfusion model that preserved the small intestine, the cecum and the ascending colon. Following reperfusion, the cecum was harvested at different time points as a representative segment of the intestine. The rats were allocated to the following four subgroups according to the reperfusion time: subgroup 1: 5 min; subgroup 2: 15 min; subgroup 3: 30 min; and subgroup 4: 60 min. A control group of cecum samples was also collected. The expression of c-fos, c-jun and immunohistochemical markers of cell proliferation and apoptosis (Ki67 and TUNEL, respectively) was studied. RESULTS: The expression of both c-fos and c-jun in the cecum was increased beginning at 5 min after ischemia-reperfusion compared with the control. The expression of c-fos began to increase at 5 min, peaked at 30 min, and exhibited a declining tendency at 60 min after reperfusion. A progressive increase in c-jun expression was observed. Immunohistochemical analyses confirmed these observations. CONCLUSION: The early activation of the c-fos and c-jun genes occurred after intestinal ischemia-reperfusion injury, and these genes can act together to trigger cell proliferation and apoptosis.