Vascular and ventilatory mechanical responses in three different stages of pulmonary development in the rabbit model of congenital diaphragmatic hernia

Abstract Purpose: To evaluate the vascular ventilatory response in different stages of lung development and to compare them to the neonates with congenital diaphragmatic hernia (CDH) in a rabbit model. Methods: New Zealand rabbits were divided into 8 groups (n=5): E25, E27, E30, and CDH. All groups were ventilated on a FlexiVent (Scireq, Montreal, QC, Canada), compounding the other 4 groups. The CDH surgery was performed at E25 and the harvest at E30. Dynamic compliance (CRS), dynamic elastance (ERS) and dynamic resistance (RRS) were measured every 4 min/24 min. Median wall thickness (MWT) and airspace were measured. ANOVA Bonferroni tests were used to perform statistical analysis. Significance was considered when p<0.05. Results: CRS was higher in E30 compared to all other groups (p<0.05). CRS and RRS of CDH and E27 were similar and were higher in E25 (p<0.05). MWT was decreased according to the gestational age, was increased in E27V and E30V (p<0.05) and decreased in CDHV (p<0.05), airspace was decreased in E25 and increased in all ventilated groups (p<0.05). Conclusions: The ventilation response of congenital diaphragmatic hernia is like the pseudoglandular stage of the lung development. These findings add information about the physiology of pulmonary ventilation in CDH.

Temporal profile of intestinal tissue expression of intestinal fatty acid-binding protein in a rat model of necrotizing enterocolitis

OBJECTIVES: Necrotizing enterocolitis is a severe multifactorial intestinal disorder that primarily affects preterm newborns, causing 20-40% mortality and morbidity. Intestinal fatty acid-binding protein has been reported to be a biomarker for the detection of intestinal injuries. Our aim was to assess intestinal tissue injury and the molecular expression of intestinal fatty acid-binding protein over time in a necrotizing enterocolitis model. METHODS: A total of 144 Newborn rats were divided into two groups: 1) Control, which received breastfeeding (n=72) and 2) Necrotizing Enterocolitis, which received formula feeding and underwent hypoxia and hypothermia (n=72). A total of six time points of ischemia (2 times a day for 3 days; 12 pups for each time point) were examined. Samples were collected for analysis of body weight, morphological and histological characteristics, intestinal weight, intestinal weight/body weight ratio, injury grade, and intestinal fatty acid-binding protein levels. RESULTS: Body and intestinal weights were lower in the Necrotizing Enterocolitis group than in the Control group (p<0.005 and p<0.0005, respectively). The intestinal weight/body weight ratio was higher in the Necrotizing Enterocolitis group than in the Control group (p<0.005) only at the sixth ischemia time point. The Necrotizing Enterocolitis group displayed higher expression of intestinal fatty acid-binding protein (p<0.0005) and showed greater tissue damage than the Control group. CONCLUSION: Intestinal fatty acid-binding protein was an efficient marker of ischemic injury to the intestine and a good correlation was demonstrated between the time of ischemic injury and the grade of intestinal injury.

Effect of hyperbaric hepatic hyperoxia on the liver of rats submitted to intermittent ischemia/reperfusion injury

PURPOSE: To determine the effect of hyperbaric hyperoxia as hepatic preconditioning on hepatocellular integrity in rats submitted to intermittent hepatic ischemia/reperfusion injury. METHODS: Twenty male Wistar rats were divided into 4 groups (SHAM, I/R, HBO-I/R and CONTROL). The surgical technique consisted of total clamping of the hepatic pedicle for 15 min, followed by reperfusion for 5 min, performed twice. The application of hyperbaric oxygen (HBO) was carried out in a collective chamber (simultaneous exposure of 4 rats) pressurized directly with oxygen at 2 ATA for 60 min. Tissue malondialdehyde (MDA) levels were determined and blood samples were collected for the determination of serum AST and ALT levels. Data were analyzed statistically by the Mann-Whitney test, with the level of significance set at p < 0.05. RESULTS: A statistically significant difference in MDA (p< 0.05) was observed between control and HBO-I/R, but not between control and I/R. Regarding AST, there was a difference between control and I/R and HBO-I/R. Analysis of ALT revealed a significant difference between control and I/R (p<0.05) and between I/R and HBO-I/R, with no difference between control and HBO-IR. CONCLUSION: Hyperoxic preconditioning proved to be favorable regarding alanine transaminase, but not aspartate aminotranserase or malondialdehyde levels. .

L-FABP and I-FABP expression in newborn rats changes inversely in the model of necrotizing enterocolitis

PURPOSE: To determine the expression of hepatic L-FABP and intestinal I-FABP in an experimental model of necrotizing enterocolitis (NEC) in neonatal rats. METHODS: Newborn Sprague-Dawley rats were divided into four groups: Control (C1) - exclusive breastfeeding at the first and sixth procedures (C6), NEC1 - fed formula milk and submitted to hypoxia and hypothermia at the first and sixth procedures (NEC6). The newborn pups were fed twice a day for three days, for a total of six procedures. Samples were collected for morphometric evaluation (body weight, liver weight, liver weight/body weight ratio, intestinal weight and intestinal/body weight ratio) and for immunohistochemical and Western blotting analysis. The values obtained were analyzed statistically, with the level of significance set at p<0.05. RESULTS: Morphometric measurements showed reduction of body and liver weights in the NEC group (p<0.05). Both immunohistochemistry and western blotting revealed that L-FABP expression in the liver was decreased and I-FABP expression in the ileum was increased in the NEC group (p<0.05). CONCLUSION: L-FABP and I-FABP expression changed inversely in the rat NEC model. These findings can contribute to a better diagnosis of NEC in human newborns. .

Prospective analysis of 44 consecutive liver transplants performed at a university hospital

PURPOSE: To analyze the intraoperative and immediate postoperative biochemical parameters of patients submitted to orthotopic liver transplantation. METHODS: Forty four consecutive orthotopic liver transplants performed from October 2009 to December 2010 were analyzed. The patients (38 male and eight female) were divided into two groups: group A, survivors, and group B, non-survivors. Fifty percent of group A patients were Chid-Pugh C, 40% Chid-Pugh B and 10% Chid-Pugh A. In group B, 52% of the patients were Chid-Pugh C, 41% Chid-Pugh B, and 17% Chid-Pugh A. All orthotopic liver transplants were performed by the piggy-back technique without a portacaval shunt in an anhepatic phase. ALT, AST, LDH and lactate levels were determined preoperatively, at five, 60 minutes after arterial revascularization of the graft and 24 and 48 hours after the end of the surgery.( or: after the surgery was finished). RESULTS: There were no preoperative clinical differences (Child and Meld) between the two groups. The times of warm and hypothermal ischemia were similar for both groups (p>0.05). Serum aminotransferases levels at five and 60 minutes after arterial revascularization of the graft were similar (p>0.05) for both groups, as also were lactate levels at the time points studied. There was no significant difference in Δ lactate between groups at any time point studied (p>0.05). No significant difference was observed between groups during the first 24 and 48 hours after surgery (p>0.05). CONCLUSION: No significant difference in any of the parameters studied was observed between groups. Under the conditions of the present study and considering the parameters evaluated, no direct relationship was detected between the intraoperative situation and the type of evolution of the patients of the two groups studied.

Effects of albumin administration in serum liver enzymes of rats in the presence of extrahepatic biliary obstruction / Efeitos da administração de albumina nos níveis séricos de enzimas hepáticas em ratos com obstrução biliar extra-hepática

PURPOSE: To study the influence of albumin on changes of liver function in the extrahepatic biliary obstruction through an experimental model in rats. METHODS: Sixty rats were divided into four groups: Group C (Control): 6 animals. Group M (Fictitious Operation): 18 rats underwent laparotomy and handling of the bile ducts; Groups O (extrahepatic biliary obstruction) and A (Treated with 2 percent albumin): 18 animals in each group underwent ligation of the ductus liver; The animals in groups M, O and A were divided into three subgroups of 6 animals each to be killed in the 7, 14 and 21 days postoperative (POD). Blood was drawn for determination of total bilirubin (TB), indirect bilirubin (IB), direct bilirubin (DB), alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). RESULTS: On POD 7, BI levels were 4.5 mg / dl in group O and 2.1 mg / dl in group A (p = 0.025). On the 14th POD, the levels of PA were 1185.2 U / l in the group and O 458.3 U / l in group A (p = 0.004). ALT levels were 101.7 U / l in the group O and 75.7 U / l in group A (= 0.037). On POD 21, the levels of ALP were 1069.5 U / l in the group O and 468.3 U / l in group A (p = 0, 004). CONCLUSION: The administration of albumin reduced the serum levels of bilirubin in the 7th day of supplementation.

OBJETIVO: Estudar a influência da albumina em alterações funcionais do fígado na obstrução biliar extra-hepática por meio de um modelo experimental desenvolvido em ratos. MÉTODOS: 60 ratos distribuídos em quatro grupos: Grupo C (Controle): 6 animais. Grupo M (Operação Fictícia): 18 ratos submetidos à laparotomia e manuseio das vias biliares; Grupos O (Obstrução Biliar Extra-hepática) e A (Tratados com albumina a 2 por cento): 18 animais, em cada grupo, submetidos à ligadura do ducto hepático; Os animais dos grupos M, O e A foram distribuídos em três subgrupos de 6 animais cada, para serem mortos nos 7°, 14° e 21° dias pós- operatórios (DPO). Foi colhido sangue para dosagem de bilirrubina total (BT), bilirrubina indireta (BI), bilirrubina direta (BD), fosfatase alcalina (FAL), aspartato aminotransferase (AST) e alanina aminotransferase (ALT). RESULTADOS: no 7º DPO, os níveis de BI foram 4,5 mg/dl no grupo O e 2,1mg/dl no grupo A (p=0,025). No 14º DPO, os níveis de FAL foram 1185,2 U/l no grupo O e 458,3 U/l no grupo A (p=0,004). Os níveis de ALT foram de 101,7 U/l no grupo O e 75,7 U/l no grupo A (=0,037). No 21º DPO, os níveis de FAL foram de 1069,5 U/l no grupo Oe de 468,3 U/l no grupo A (p =0, 004). CONCLUSÃO: a administração de albumina reduziu os níveis séricos de bilirrubina indireta no 7°dia de suplementação.

Biochemical liver function after partial hepatic resection with or without partial hepatic vascular exclusion / Função bioquímica do fígado após ressecção hepática parcial com ou sem exclusão vascular hepática parcial

PURPOSE: The aim of the present study was to assess the advantages and disadvantages of liver vascular partial exclusion (LVPE) (liver dysfunction due to ischemia) during liver resection in patients submitted to partial hepatectomy. METHODS: A total of 114 patients were submitted to partial hepatectomy (minor versus major resections) with LPVE being used in 57 of them but not in the remaining 57. Patient age ranged from 35 to 73 years and 57 percent were women. Mitochondrial function was assessed 30 minutes after liver resection in the remnant liver and serum aminotransferases were determined before surgery and for seven days postoperatively. LPVE time ranged from 30 to 60 minutes. Data were analyzed statistically by the Student T test (5 percent level of significance). RESULTS: Mitochondrial function was similar in the minor and major liver resections. The maximum postoperative aminotransferase peak was similar in the groups with and without LPVE. CONCLUSION: LPVE did not induce mitochondrial changes in hepatic tissue in either type of surgery, and aminotransferase levels were similar for patients with and without LPVE. Thus, the results show that LPVE is a safe procedure that does not induce the significant changes typical of ischemia and reperfusion in the liver remnant.

OBJETIVO: Avaliar as vantagens e desvantagens da oclusão vascular parcial do fígado durante ressecções hepáticas parciais. MÉTODOS: Cento e quatorze pacientes foram submetidos a hepatectomia parcial(ressecção maior versus ressecção menor) com liver partial vascular exclusion (LPVE) sendo utilizada em 57 deles. A idade dos pacientes variou entre 35 e 73 anos e 57 por cento deles eram mulheres. A função mitocondrial foi avaliada por método polarografico avaliada 30 minutos após a ressecção hepática no fígado remanescente, e o perfil das aminotransferase foi determinado antes da cirurgia e durante sete dias de pós-operatório. A EVPH variou de 30 a 60 minutos. Dados foram analisados estatisticamente pelo teste T Student (nível de significância de 5 por cento). RESULTADOS: Nas ressecções hepáticas maiores e menores, a função mitocondrial do fígado remanescente foi semelhante dos dois grupos. O pico máximo de aminotransferases ocorreu as 24 horas de pós-operatório e o perfil enzimático de ALT e AST foi semelhante nos grupos estudados ( minor vs major hepatectomy.) CONCLUSÃO: A EVPH não induziu alterações mitocondriais no tecido hepático em qualquer tipo de cirurgia, e os níveis de aminotransferases foram similares para pacientes hepatectomizados com e sem LPVE.Assim a LPVE foi um procedimento seguro que não induziu alterações significativas típicos de isquemia e reperfusão no fígado remanescente.