Peritoneal free autologous fat graft for the control of pulmonary air leaks in emphysematous rat lungs.

BACKGROUND: Persistent pulmonary air leak is the most frequent complication after lung resection, resulting in an increase in postoperative morbidity and mortality. We evaluated the viability, integration, and efficacy of a free peritoneal fat graft as a method for controlling air leak in normal and emphysematous rat lungs. METHODS: Sixty Wistar rats were divided into two groups: elastase-produced lung emphysema (n=30) and control (normal) lungs (n=30). Pulmonary air leak was produced by puncture of the right lower lobe, and aerostasis was attempted by means of intrapulmonary injection of autologous free peritoneal fat graft. Rats in each group (n=6) were randomly allocated to subgroups and were sacrificed at 7, 14, 21, 30, and 60 days. Then, lungs were removed for histology, morphometry, vessel identification and counting, and immunohistochemistry for caspase 3, vascular endothelial growth factor, and factor VIII. RESULTS: Tissue integration of the free fat grafts was found in all animals in both groups. Vessels stained with India ink inside the fat grafts were present at all assessment periods in both groups. Vascular endothelial growth factor expression was significantly higher in all periods in the emphysema group compared with normal lungs (p<0.001). There was a significant increase in caspase 3 expression in the emphysema group at 7, 21, 30, and 60 days (p<0.001). Factor VIII showed a significant increase (p<0.001) at 30 and 60 days in emphysematous lungs. CONCLUSIONS: The use of free peritoneal fat graft was able to control the air leaks in normal and emphysematous rat lungs, with persisting graft viability for as long as 60 days after implantation.

Impairment of short term memory in rats with hepatic encephalopathy due to bile duct ligation.

Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to cognitive deficits. Different animal models for the study of HE have demonstrated learning and memory impairment and a number of neurotransmitter systems have been proposed to be involved in this. Recently, it was described that bile duct-ligated (BDL) rats exhibited altered spatio-temporal locomotor and exploratory activities and biosynthesis of neurotransmitter GABA in brain cortices. Therefore, the aim of this study was to evaluate cognition in the same animal model. Male adult Wistar rats underwent common bile duct ligation (BDL rats) or manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent object recognition behavioral task. The BDL rats developed chronic liver failure and exhibited a decreased discrimination index for short term memory (STM) when compared to the control group. There was no difference in long term memory (LTM) as well as in total time of exploration in the training, STM and LTM sessions between the BDL and control rats. Therefore, the BDL rats demonstrated impaired STM for recognition memory, which was not due to decreased exploration.