Effects of local and remote ischemic postconditioning methods on ischemiareperfusion injury in a young animal model of acute mesenteric ischemia

Purpose: Acute mesenteric ischemia (AMI) is a condition in pediatric surgery that ranges from intestine necrosis to death. Ischemic postconditioning (IPoC) methods were developed to reduce the damage caused by revascularization. This study aimed to evaluate the efficacy of these methods in an experimental weaning rat model. Methods: Thirty-two 21-day-old Wistar rats were allocated into four groups according to the surgical procedure performed: control, ischemia-reperfusion injury (IRI), local (LIPoC) and remote IPoC (RIPoC). At euthanasia, fragments of the intestine, liver, lungs, and kidneys were submitted to histological, histomorphometric, and molecular analyses. Results: In the duodenum, intestines, and kidneys histological alterations promoted by IRI were reversed by remote postconditioning method. In the distal ileum, the histomorphometric alterations could be reversed by the postconditioning methods with more evident effects promoted by the remote method. The molecular analysis found that the levels of expression of Bax (proapoptotic) and Bcl-XL (antiapoptotic) genes in the intestine were increased by IRI. These alterations were equally reversed by the postconditioning methods, with more evident effects of the remote method. Conclusions: IPoC methods positively reduced the damage caused by IRI in weaning rats.

Microsurgical arterial anastomosis in young and adult rats: an evolutive and comparative study

Purpose: To evaluate the caliber of an arterial micro-anastomosis in the young growing animal using a continuous suture technique. Additionally, late morphological changes and blood flows distal to the anastomosis were evaluated. Methods: Seventy-four Wistar rats were submitted to laparotomy to access the aorta for blood flow measurement. The aorta was sectioned using microsurgery technique and an end-to-end anastomosis with continuous suture. After a period of six months to one year, the anastomosis was checked. Results: Regarding the size of the aortas, comparing the pre- and postoperative values, there was an increase of 13.33% in adult animals and 25% in young animals, without any difference in the blood flows. Conclusions: The arteries of young rats show signs of growth at the site of the anastomosis performed with continuous suture.

Cardiac and renal effects of liver cirrhosis in a growing animal model

ABSTRACT Purpose: To assess the biochemical, histological, histomorphometric and molecular effects of biliary duct ligation (BDL) induced liver cirrhosis in the heart and kidneys. Methods: Thirty-two weaning rats (21 days old, 50-70 g) underwent BDL and were divided in four groups (euthanasia after two, four, six, and eight weeks, respectively) and compared to control groups. Results: The animals' hearts of group 3 were bigger than those of the control group (p=0.042), including thinner right ventricle wall, decreased internal diameter of ventricles, and increased perivascular collagen deposition in left ventricle, as well as increased interstitial collagen in right ventricle after six weeks. In the kidneys of groups 3 and 4, bilirubin impregnation in the tubules, hydropic degeneration, loss of nuclei and lack of plasmatic membrane limits were noted. Nitric oxide synthase (NOS) gene expressions were higher in group 1 (p=0.008), and endothelial nitric oxide synthase (eNOS) gene expressions were elevated in all experimental groups (p=0.008, p=0.001, p=0.022, and p=0.013, respectively). In the heart, a decreased expression of eNOS in group 1 (p=0.04) was observed. Conclusions: Liver cirrhosis leads to histological and histomorphometric alterations in the heart and kidneys, with changes in the NOS and eNOS gene expressions, that may suggest a role in the associated myocardial and renal manifestations.

Early parenteral nutrition in enterectomized dogs / Nutrição parenteral precoce em cães submetidos à enterectomia

The aim of this study was to explore the role of early central parenteral nutrition support with and without lipid emulsion in enterectomized dogs undergoing small bowel partial resection. Enterectomized dogs often cannot be fed properly via an oral or enteral route immediately post-surgery. After enterectomy, the animals received parenteral nutrition or crystalloid solution until they were able to voluntarily take in an oral diet. All dogs were recruited at the University of Sao Paulo veterinary teaching hospital. Eighteen dogs with intussusception, a foreign intestinal body, linear foreign intestinal body, or intussusception associated with a foreign intestinal body underwent enterectomy surgery and were randomly assigned to receive one of three treatments: crystalloid solution (CS group), parenteral nutrition with a mix of glucose and amino acids (GA group) or parenteral nutrition with a mix of glucose, amino acids and lipids (GAL group). A serum chemistry panel and complete blood count were collected prior to surgery and at the end of the study. Albumin increased in the GA and GAL group (p=0.042 and p=0.038 respectively) after hospitalization, but no significant differences were identified among the groups. Body weight decreased by 4.9% (p=0.042) in the CS group, but there were no significant changes in the GAL and GA groups. There was a significant decrease in the recovery scores in the GA and GAL groups during hospitalization (p=0.039 in both groups). Early parenteral nutrition was beneficial for patient recovery in post-surgical small bowel partial resection, indicating better quality, and no major complications or side effects were observed during the hospitalization period in the studied dogs.(AU)

O objetivo desse estudo era estudar os efeitos da nutrição parenteral central precoce com e sem emulsão lipídica em cães submetidos à ressecção parcial do intestino delgado. Os cães enterectomizados frequentemente não conseguem ser adequadamente alimentados por via oral ou enteral no pós-cirúrgico imediato. Após a enterectomia, os animais receberam nutrição parenteral ou solução cristaloide até o momento em que fossem capazes de alimentar-se voluntariamente por via oral. Todos os animais foram selecionados no hospital veterinário da Universidade de São Paulo. Dezoito cães diagnosticados com intussuscepção, corpo estranho intestinal, corpo estranho linear ou intussuscepção associada com corpo estranho intestinal foram submetidos à enterectomia e aleatoriamente alocados para receber um dos três tratamentos: solução cristaloide (grupo CS), nutrição parenteral com mistura de glicose e aminoácidos (grupo GA) ou nutrição parental com mistura de glicose e lipídios (grupo GAL). Hemograma e bioquímica sérica foram coletados antes da cirurgia e no final do estudo. Houve aumento de albumina no grupo GA e GAL (p=0,042 e p=0,038 respectivamente) após a hospitalização, mas não houve diferença significativa entre grupos. O peso corpóreo diminuiu cerca de 4,9% (p=0,042) no grupo CS mas não houve alterações significativas no grupo GAL e GA. Houve uma diminuição significativa no escore de recuperação no grupo GA e GAL durante a hospitalização (p=0,039 em ambos os grupos). A nutrição parenteral precoce mostrou-se benéfica para a recuperação no pós-operatório dos cães submetidos à ressecção parcial do intestino delgado, sinalizando uma melhora na qualidade da recuperação e ausência de grandes complicações ou efeitos colaterais durante o período de hospitalização dos animais estudados.(AU)

Early parenteral nutrition in enterectomized dogs / Nutrição parenteral precoce em cães submetidos à enterectomia

The aim of this study was to explore the role of early central parenteral nutrition support with and without lipid emulsion in enterectomized dogs undergoing small bowel partial resection. Enterectomized dogs often cannot be fed properly via an oral or enteral route immediately post-surgery. After enterectomy, the animals received parenteral nutrition or crystalloid solution until they were able to voluntarily take in an oral diet. All dogs were recruited at the University of Sao Paulo veterinary teaching hospital. Eighteen dogs with intussusception, a foreign intestinal body, linear foreign intestinal body, or intussusception associated with a foreign intestinal body underwent enterectomy surgery and were randomly assigned to receive one of three treatments: crystalloid solution (CS group), parenteral nutrition with a mix of glucose and amino acids (GA group) or parenteral nutrition with a mix of glucose, amino acids and lipids (GAL group). A serum chemistry panel and complete blood count were collected prior to surgery and at the end of the study. Albumin increased in the GA and GAL group (p=0.042 and p=0.038 respectively) after hospitalization, but no significant differences were identified among the groups. Body weight decreased by 4.9% (p=0.042) in the CS group, but there were no significant changes in the GAL and GA groups. There was a significant decrease in the recovery scores in the GA and GAL groups during hospitalization (p=0.039 in both groups). Early parenteral nutrition was beneficial for patient recovery in post-surgical small bowel partial resection, indicating better quality, and no major complications or side effects were observed during the hospitalization period in the studied dogs.(AU)

O objetivo desse estudo era estudar os efeitos da nutrição parenteral central precoce com e sem emulsão lipídica em cães submetidos à ressecção parcial do intestino delgado. Os cães enterectomizados frequentemente não conseguem ser adequadamente alimentados por via oral ou enteral no pós-cirúrgico imediato. Após a enterectomia, os animais receberam nutrição parenteral ou solução cristaloide até o momento em que fossem capazes de alimentar-se voluntariamente por via oral. Todos os animais foram selecionados no hospital veterinário da Universidade de São Paulo. Dezoito cães diagnosticados com intussuscepção, corpo estranho intestinal, corpo estranho linear ou intussuscepção associada com corpo estranho intestinal foram submetidos à enterectomia e aleatoriamente alocados para receber um dos três tratamentos: solução cristaloide (grupo CS), nutrição parenteral com mistura de glicose e aminoácidos (grupo GA) ou nutrição parental com mistura de glicose e lipídios (grupo GAL). Hemograma e bioquímica sérica foram coletados antes da cirurgia e no final do estudo. Houve aumento de albumina no grupo GA e GAL (p=0,042 e p=0,038 respectivamente) após a hospitalização, mas não houve diferença significativa entre grupos. O peso corpóreo diminuiu cerca de 4,9% (p=0,042) no grupo CS mas não houve alterações significativas no grupo GAL e GA. Houve uma diminuição significativa no escore de recuperação no grupo GA e GAL durante a hospitalização (p=0,039 em ambos os grupos). A nutrição parenteral precoce mostrou-se benéfica para a recuperação no pós-operatório dos cães submetidos à ressecção parcial do intestino delgado, sinalizando uma melhora na qualidade da recuperação e ausência de grandes complicações ou efeitos colaterais durante o período de hospitalização dos animais estudados.(AU)