Ischemic Postconditioning Assessment in the Liver of Rats Undergoing Mesenteric Ischemia and Reperfusion.

Introduction: Ischemic postconditioning is a method that shows evidence of efficacy in minimizing reperfusion injury; however, its effectiveness in preventing injuries in distant organs is still unknown, especially in those who have undergone mesenteric ischemia and reperfusion. Objective: To evaluate the effect of ischemic postconditioning in preventing reperfusion injury in the liver of rats submitted to mesenteric ischemia and reperfusion, comparing two different methods of ischemic postconditioning. Methods: 30 Wistar male rats were used, distributed into three groups: Group A: Ten rats submitted to intestinal ischemia for 30 minutes followed by reperfusion for 60 minutes; Group B: Ten rats subjected to ischemia and reperfusion; after ischemia, two cycles of reperfusion (two minutes each) interleaved with two cycles of ischemia (two minutes each); and Group C: Ten rats subjected to ischemia and reperfusion; after ischemia, four cycles of reperfusion (30 seconds each) interspersed with four cycles of ischemia (30 seconds each). After the experiment, the left lobe of the liver was resected for subsequent histological analysis, using the following classification: grade 1 - centrilobular congestion; grade 2 - centrilobular congestion with some degeneration of hepatocytes in one or two central veins; and grade 3 - multifocal centrilobular congestion and degeneration of portal hepatocytes. Results: The mean degree of liver damage found was 1.8 in group A, 1.7 in group B and 1.3 in group C. There was no statistically significant difference between the groups. Conclusion: Ischemic postconditioning was unable to minimize reperfusion injury in rats undergoing mesenteric ischemia and reperfusion.

Ischemic postconditioning assessment in the liver of rats undergoing mesenteric ischemia and reperfusion

Abstract Introduction: Ischemic postconditioning is a method that shows evidence of efficacy in minimizing reperfusion injury; however, its effectiveness in preventing injuries in distant organs is still unknown, especially in those who have undergone mesenteric ischemia and reperfusion. Objective: To evaluate the effect of ischemic postconditioning in preventing reperfusion injury in the liver of rats submitted to mesenteric ischemia and reperfusion, comparing two different methods of ischemic postconditioning. Methods: 30 Wistar male rats were used, distributed into three groups: Group A: Ten rats submitted to intestinal ischemia for 30 minutes followed by reperfusion for 60 minutes; Group B: Ten rats subjected to ischemia and reperfusion; after ischemia, two cycles of reperfusion (two minutes each) interleaved with two cycles of ischemia (two minutes each); and Group C: Ten rats subjected to ischemia and reperfusion; after ischemia, four cycles of reperfusion (30 seconds each) interspersed with four cycles of ischemia (30 seconds each). After the experiment, the left lobe of the liver was resected for subsequent histological analysis, using the following classification: grade 1 - centrilobular congestion; grade 2 - centrilobular congestion with some degeneration of hepatocytes in one or two central veins; and grade 3 - multifocal centrilobular congestion and degeneration of portal hepatocytes. Results: The mean degree of liver damage found was 1.8 in group A, 1.7 in group B and 1.3 in group C. There was no statistically significant difference between the groups. Conclusion: Ischemic postconditioning was unable to minimize reperfusion injury in rats undergoing mesenteric ischemia and reperfusion.

Importance of duration and number of ischemic postconditioning cycles in preventing reperfusion mesenteric injuries. Experimental study in rats.

PURPOSE: To evaluate the effect of ischemic postconditioning(IPC) on intestinal mucosa of rats subjected to ischemia and reperfusion process comparing two cycles of reperfusion and ischemia lasting two minutes each and four cycles of reperfusion and ischemia lasting 30 seconds each. METHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion plus IPC by two lasting two minutes each; and Group C (10 rats), ischemia and reperfusion plus IPC by four cycles lasting 30 seconds each. Finally, a segment of small intestine was resected for histological analysis. We analysed the results according to Chiu et al. classification and proceeded to the statistical treatment by Kruskal-Wallis test (p<0.05). RESULTS: The mean degree of tissue injury according to Chiu et al. classification were: Group A, 2.77; in group B, 1.4; and group C, 1.4. B X C (p<0.05). CONCLUSIONS: Ischemic postconditioning was able to minimize reperfusion injury of rats undergone mesenteric ischemia and reperfusion process. There was no difference in the effectiveness of the method comparing two cycles of two minutes with four cycles of 30 seconds by H&E histological evaluation of the ileum after 60-minute reperfusion.

Evaluation of Pulmonary Reperfusion Injury in Rats Undergoing Mesenteric Ischemia and Reperfusion and Protective Effect of Postconditioning on this Process

ABSTRACT INTRODUCTION: Some publications have demonstrated the presence of lung reperfusion injury in mesenteric ischemia and reperfusion (I/R), but under to diverse methods. Postconditioning has been recognized as effective in preventing reperfusion injury in various organs and tissues. However, its effectiveness has not been evaluated in the prevention of lung reperfusion injury after mesenteric ischemia and reperfusion. OBJECTIVE: To evaluate the presence of pulmonary reperfusion injury and the protective effect of ischemic postconditioning on lung parenchyma in rats submitted to mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), which was held mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion, interspersed by postconditioning with two alternating cycles of reperfusion and reocclusion, for two minutes each; and group C (10 rats), ischemia and reperfusion interleaved by postconditioning with four alternating cycles of reperfusion and reocclusion of 30 seconds each. Finally, it was resected the upper lung lobe for histological analysis. RESULTS: There were mild lung lesions (grade 1) in all samples. There was no statistical difference between groups 1 and 2 (P >0.05). CONCLUSION: The mesenteric ischemia and reperfusion in rats for thirty and sixty minutes, respectively, caused mild reperfusion injury in lung. Postconditioning was not able to minimize the remote reperfusion injury and there was no difference comparing two cycles of two minutes with four cycles of 30 seconds.

Importance of duration and number of ischemic postconditioning cycles in preventing reperfusion mesenteric injuries. Experimental study in rats

PURPOSE:To evaluate the effect of ischemic postconditioning(IPC) on intestinal mucosa of rats subjected to ischemia and reperfusion process comparing two cycles of reperfusion and ischemia lasting two minutes each and four cycles of reperfusion and ischemia lasting 30 seconds eachMETHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion plus IPC by two lasting two minutes each; and Group C (10 rats), ischemia and reperfusion plus IPC by four cycles lasting 30 seconds each. Finally, a segment of small intestine was resected for histological analysis. We analysed the results according to Chiu et al. classification and proceeded to the statistical treatment by Kruskal-Wallis test (p<0.05).RESULTS: The mean degree of tissue injury according to Chiu et al. classification were: Group A, 2.77; in group B, 1.4; and group C, 1.4. B X C (p<0.05).CONCLUSIONS: Ischemic postconditioning was able to minimize reperfusion injury of rats undergone mesenteric ischemia and reperfusion process. There was no difference in the effectiveness of the method comparing two cycles of two minutes with four cycles of 30 seconds by H&E histological evaluation of the ileum after 60-minute reperfusion.

Importance of duration and number of ischemic postconditioning cycles in preventing reperfusion mesenteric injuries. Experimental study in rats

To evaluate the effect of ischemic postconditioning (IPC) on intestinal mucosa of rats subjected to ischemia and reperfusion process comparing two cycles of reperfusion and ischemia lasting two minutes each and four cycles of reperfusion and ischemia lasting 30 seconds each METHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion plus IPC by two lasting two minutes each; and Group C (10 rats), ischemia and reperfusion plus IPC by four cycles lasting 30 seconds each. Finally, a segment of small intestine was resected for histological analysis. We analysed the results according to Chiu et al . classification and proceeded to the statistical treatment by Kruskal-Wallis test (p 0.05). RESULTS: The mean degree of tissue injury according to Chiu et al . classification were: Group A, 2.77; in group B, 1.4; and group C, 1.4. B X C (p 0.05). CONCLUSIONS: Ischemic postconditioning was able to minimize reperfusion injury of rats undergone mesenteric ischemia and reperfusion process. There was no difference in the effectiveness of the method comparing two cycles of two minutes with four cycles of 30 seconds by H&E histological evaluation of the ileum after 60-minute reperfusion.(AU)

Evaluation of Pulmonary Reperfusion Injury in Rats Undergoing Mesenteric Ischemia and Reperfusion and Protective Effect of Postconditioning on this Process.

INTRODUCTION: Some publications have demonstrated the presence of lung reperfusion injury in mesenteric ischemia and reperfusion (I/R), but under to diverse methods. Postconditioning has been recognized as effective in preventing reperfusion injury in various organs and tissues. However, its effectiveness has not been evaluated in the prevention of lung reperfusion injury after mesenteric ischemia and reperfusion. OBJECTIVE: To evaluate the presence of pulmonary reperfusion injury and the protective effect of ischemic postconditioning on lung parenchyma in rats submitted to mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), which was held mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion, interspersed by postconditioning with two alternating cycles of reperfusion and reocclusion, for two minutes each; and group C (10 rats), ischemia and reperfusion interleaved by postconditioning with four alternating cycles of reperfusion and reocclusion of 30 seconds each. Finally, it was resected the upper lung lobe for histological analysis. RESULTS: There were mild lung lesions (grade 1) in all samples. There was no statistical difference between groups 1 and 2 (P >0.05). CONCLUSION: The mesenteric ischemia and reperfusion in rats for thirty and sixty minutes, respectively, caused mild reperfusion injury in lung. Postconditioning was not able to minimize the remote reperfusion injury and there was no difference comparing two cycles of two minutes with four cycles of 30 seconds.

Very short cycles of postconditioning have no protective effect against reperfusion injury. Experimental study in rats / Ciclos muito curtos de pós-condicionamento não protegem contra lesão de reperfusão. Estudo experimental em ratos

Introduction: Ischemic postconditioning has been recognized as effective in the prevention of reperfusion injury in situations of ischemia and reperfusion in various organs and tissues. However, it remains unclear what would be the best way to accomplish it, since studies show great variation in the method of their application. Objective: To assess the protective effect of ischemic postconditioning on ischemia and reperfusion in rats undergoing five alternating cycles of reperfusion and ischemia of 30 seconds each one. Methods: We studied 25 Wistar rats distributed in three groups: group A (10 rats), which underwent mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B (10 rats), undergoing ischemia (30 minutes) and reperfusion (60 minutes), intercalated by postconditioning (5 alternating cycles of reperfusion and ischemia of 30 seconds each one); and group C - SHAM (5 rats), undergoing only laparotomy and manipulation of mesenteric artery. All animals underwent resection of an ileum segment for histological analysis. Results: The mean lesions degree according to Chiu et al. were: group A, 2.77, group B, 2.67 and group C, 0.12. There was no difference between groups A and B (P>0.05). Conclusion: Ischemic postconditioning was not able to minimize or prevent the intestinal tissue injury in rats undergoing ischemia and reperfusion process when used five cycles lasting 30 seconds each one. .

Introdução: O pós-condicionamento isquêmico tem sido reconhecido como eficaz na prevenção das lesões de reperfusão em situações de isquemia e reperfusão em vários órgãos e tecidos. Entretanto, não está ainda claro qual seria a melhor maneira de realizá-lo, já que as publicações mostram grande variação de método no seu emprego. Objetivo: Avaliar o efeito protetor do pós-condicionamento isquêmico na isquemia e reperfusão intestinal em ratos, através de cinco ciclos alternados de 30 segundos de isquemia e 30 segundos de reperfusão. Métodos: Foram estudados 25 ratos Wistar, distribuídos em três grupos: grupo A (10 ratos), em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B (10 ratos), isquemia e reperfusão, seguidos de pós-condicionamento isquêmico com 5 ciclos alternados de reperfusão e reoclusão, de 30 segundos cada; e grupo C (5 ratos), controle (SHAM). Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu et al. e procedeu-se ao tratamento estatístico. Resultados: As médias dos graus de lesão tecidual segundo a classificação de Chiu et al. foram: no grupo A, 2,77; no grupo B, 2,67; e no grupo C, 0,12. A diferença entre o resultado do grupo A com o resultado do grupo B não teve significância estatística (P>0,05). Conclusão: O pós-condicionamento isquêmico não foi capaz de minimizar ou prevenir a lesão tecidual intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica quando utilizados cinco ciclos com duração de 30 segundos cada. .

Very short cycles of postconditioning have no protective effect against reperfusion injury. Experimental study in rats.

INTRODUCTION: Ischemic postconditioning has been recognized as effective in the prevention of reperfusion injury in situations of ischemia and reperfusion in various organs and tissues. However, it remains unclear what would be the best way to accomplish it, since studies show great variation in the method of their application. OBJECTIVE: To assess the protective effect of ischemic postconditioning on ischemia and reperfusion in rats undergoing five alternating cycles of reperfusion and ischemia of 30 seconds each one. METHODS: We studied 25 Wistar rats distributed in three groups: group A (10 rats), which underwent mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B (10 rats), undergoing ischemia (30 minutes) and reperfusion (60 minutes), intercalated by postconditioning (5 alternating cycles of reperfusion and ischemia of 30 seconds each one); and group C - SHAM (5 rats), undergoing only laparotomy and manipulation of mesenteric artery. All animals underwent resection of an ileum segment for histological analysis. RESULTS: The mean lesions degree according to Chiu et al. were: group A, 2.77, group B, 2.67 and group C, 0.12. There was no difference between groups A and B (P>0.05). CONCLUSION: Ischemic postconditioning was not able to minimize or prevent the intestinal tissue injury in rats undergoing ischemia and reperfusion process when used five cycles lasting 30 seconds each one.

Chemoembolisation combined with percutaneous radiofrequency ablation in the treatment of primary angiosarcoma of the liver.

Angiosarcoma of the liver is a rare disease; however, it ranks as the third most common primary liver malignancy. Diagnosis is difficult and prognosis is very poor. After the onset of clinical symptoms, the disease often progresses rapidly, decreasing the chances of curative treatment. We report the case of an 83-year-old male patient who presented with postprandial fullness. Upper abdominal ultrasound showed a hypervascular mass in segment 6 of the liver. The results of anatomopathological examination and immunohistochemistry were compatible with the diagnosis of primary angiosarcoma of the liver. Patient refused surgery (haepatectomy), and treatment was then initiated with transarterial chemoembolisation, followed by percutaneous radiofrequency ablation. The patient is currently cured based on clinical and radiological evidence. This case report is the first in the literature to describe the combined use of transarterial chemoembolisation with percutaneous radiofrequency ablation in the treatment of primary angiosarcoma of the liver.

Isolated metachronous splenic metastasis from renal cell carcinoma after 5 years.

Primary and metastatic tumours of the spleen are uncommon. The incidence of isolated metastasis from other organs is less than 1%. We report the case of a 55-year-old woman with clear cell carcinoma of the kidney, who underwent radical nephrectomy. After a 5-year follow-up period, a hypervascular nodule was detected in the spleen on MRI. Six months later, control MRI showed that its appearance had changed to a hypervascular mass with areas of central necrosis. A splenectomy was performed and histopathological examination of the spleen confirmed the presence of clear cell carcinoma with infiltration of the capsule. This is only the seventh case described in the literature of isolated splenic metastasis from clear cell carcinoma and the first such case containing MRI.

Postconditioning effect in the hepatic ischemia and reperfusion in rats / Efeito do pós-condicionamento isquêmico sobre a isquemia e reperfusão hepática em ratos

Purpose: To evaluate the effect of postconditioning protection in liver tissue of rats submitted to ischemia and reperfusion. Methods: 25 Wistar male rats were randomized in three groups: Group A (ischemia and reperfusion - I/R), with 10 rats, which was made ischemia by vascular clamp application in hepatic hilum for 30 minutes and reperfusion for 60 minutes by removal of the clamp; Group B (Postconditioning - IPo), with 10 rats, with same procedure plus postconditioning (3 cycles of reperfusion inserted by 3 cycles of ischemia, 30 seconds for each phase, between ischemia and reperfusion phases); and Group C (Sham), with 5 rats, which took place only laparotomy and manipulation of the hepatic hilum. Specimens were examined (histological evaluation) and dosage of serum AST and ALT was made. The statistical analysis was made with t Student test, with significant difference when p<0.05. Results: In the Sham group there was no histological or enzymatic changes; In group A the mean tissue lesion was 1.6 and in group B 1.1 (p=0.014). In group A the mean ALT level was 355U/l and in group B was 175.9U/l (p=0.016). The mean of AST was 828.8U/l in group A and 295.5U/l in group B (p=0.001). Conclusion: The postconditioning was able to minimize the severity of liver injury in rats submitted to ischemia and reperfusion.

Objetivo: Avaliar o efeito do pós-condicionamento isquêmico na proteção tecidual hepática de ratos submetidos à isquemia e reperfusão. Métodos: Foram utilizados 25 ratos da linhagem Wistar provenientes do Biotério da Universidade Federal de Mato Grosso do Sul, distribuídos em três grupos: A) grupo isquemia/reperfusão (I/R) (10 ratos), em que foi realizada isquemia e reperfusão hepática pela aplicação e retirada de clampe do hilo hepático durante 30 e 60 minutos, respectivamente; B) grupo pós-condicionamento isquêmico (PoCI) (10 ratos), em que foi realizado procedimento semelhante ao anterior, exceto pela realização do pós-condicionamento isquêmico entre as fases de isquemia e reperfusão, consistindo na retirada e colocação do clampe do hilo hepático por 30 segundos cada fase, durante 3 ciclos; grupo C (Sham) (5 ratos), em que realizou-se apenas laparotomia e manipulação do hilo hepático. Foram analisados os espécimes (avaliação histológica), dosagem sorológica de AST e ALT. Resultados: No grupo Sham não se observou alterações histológicas nem enzimáticas; no grupo A a média de lesão tecidual foi 1,6 e no grupo B 1,1 (p=0,014). No grupo A a média de ALT foi 355U/l e no grupo B 175,9U/l (p=0,016). A média de AST foi de 582,8U/l no grupo A e 295,5U/l no grupo B (p=0,001). Conclusão: O pós-condicionamento isquêmico foi capaz de minimizar a intensidade das lesões hepáticas de ratos submetidos à isquemia e reperfusão.

Postconditioning effect in the hepatic ischemia and reperfusion in rats / Efeito do pós-condicionamento isquêmico sobre a isquemia e reperfusão hepática em ratos

Purpose: To evaluate the effect of postconditioning protection in liver tissue of rats submitted to ischemia and reperfusion. Methods: 25 Wistar male rats were randomized in three groups: Group A (ischemia and reperfusion - I/R), with 10 rats, which was made ischemia by vascular clamp application in hepatic hilum for 30 minutes and reperfusion for 60 minutes by removal of the clamp; Group B (Postconditioning - IPo), with 10 rats, with same procedure plus postconditioning (3 cycles of reperfusion inserted by 3 cycles of ischemia, 30 seconds for each phase, between ischemia and reperfusion phases); and Group C (Sham), with 5 rats, which took place only laparotomy and manipulation of the hepatic hilum. Specimens were examined (histological evaluation) and dosage of serum AST and ALT was made. The statistical analysis was made with t Student test, with significant difference when p<0.05. Results: In the Sham group there was no histological or enzymatic changes; In group A the mean tissue lesion was 1.6 and in group B 1.1 (p=0.014). In group A the mean ALT level was 355U/l and in group B was 175.9U/l (p=0.016). The mean of AST was 828.8U/l in group A and 295.5U/l in group B (p=0.001). Conclusion: The postconditioning was able to minimize the severity of liver injury in rats submitted to ischemia and reperfusion.(AU)

Objetivo: Avaliar o efeito do pós-condicionamento isquêmico na proteção tecidual hepática de ratos submetidos à isquemia e reperfusão. Métodos: Foram utilizados 25 ratos da linhagem Wistar provenientes do Biotério da Universidade Federal de Mato Grosso do Sul, distribuídos em três grupos: A) grupo isquemia/reperfusão (I/R) (10 ratos), em que foi realizada isquemia e reperfusão hepática pela aplicação e retirada de clampe do hilo hepático durante 30 e 60 minutos, respectivamente; B) grupo pós-condicionamento isquêmico (PoCI) (10 ratos), em que foi realizado procedimento semelhante ao anterior, exceto pela realização do pós-condicionamento isquêmico entre as fases de isquemia e reperfusão, consistindo na retirada e colocação do clampe do hilo hepático por 30 segundos cada fase, durante 3 ciclos; grupo C (Sham) (5 ratos), em que realizou-se apenas laparotomia e manipulação do hilo hepático. Foram analisados os espécimes (avaliação histológica), dosagem sorológica de AST e ALT. Resultados: No grupo Sham não se observou alterações histológicas nem enzimáticas; no grupo A a média de lesão tecidual foi 1,6 e no grupo B 1,1 (p=0,014). No grupo A a média de ALT foi 355U/l e no grupo B 175,9U/l (p=0,016). A média de AST foi de 582,8U/l no grupo A e 295,5U/l no grupo B (p=0,001). Conclusão: O pós-condicionamento isquêmico foi capaz de minimizar a intensidade das lesões hepáticas de ratos submetidos à isquemia e reperfusão.(AU)

Postconditioning effect in the hepatic ischemia and reperfusion in rats.

PURPOSE: To evaluate the effect of postconditioning protection in liver tissue of rats submitted to ischemia and reperfusion. METHODS: 25 Wistar male rats were randomized in three groups: Group A (ischemia and reperfusion - I/R), with 10 rats, which was made ischemia by vascular clamp application in hepatic hilum for 30 minutes and reperfusion for 60 minutes by removal of the clamp; Group B (Postconditioning - IPo), with 10 rats, with same procedure plus postconditioning (3 cycles of reperfusion inserted by 3 cycles of ischemia, 30 seconds for each phase, between ischemia and reperfusion phases); and Group C (Sham), with 5 rats, which took place only laparotomy and manipulation of the hepatic hilum. Specimens were examined (histological evaluation) and dosage of serum AST and ALT was made. The statistical analysis was made with t Student test, with significant difference when p<0.05. RESULTS: In the Sham group there was no histological or enzymatic changes; In group A the mean tissue lesion was 1.6 and in group B 1.1 (p=0.014). In group A the mean ALT level was 355U/l and in group B was 175.9U/l (p=0.016). The mean of AST was 828.8U/l in group A and 295.5U/l in group B (p=0.001). CONCLUSION: The postconditioning was able to minimize the severity of liver injury in rats submitted to ischemia and reperfusion.

Evaluation of ischemic postconditioning effect on mesenteric ischemia treatment: experimental study in rats.

OBJECTIVE: To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure. METHODS: Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed. RESULTS: According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05). CONCLUSION: Ischemic pre- and postconditioning were capable of minimizing - in a similar intensity - the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process.

Avaliação do pós-condicionamento isquêmico no tratamento da isquemia mesentérica: estudo experimental em ratos / Evaluation of ischemic postconditioning effect on mesenteric ischemia treatment: experimental study in rats

OBJETIVO: Avaliar o efeito do pré e pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. MÉTODOS: Foram estudados 30 ratos Wistar, distribuídos em três grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica precedidos pelo pré-condicionamento isquêmico por três ciclos de isquemia e reperfusão com duração de dois minutos cada; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico por três ciclos de reperfusão e isquemia com duração de dois minutos cada. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu et al. e procedeu-se ao tratamento estatístico. RESULTADOS: As médias dos graus de lesão tecidual segundo a classificação de Chiu et al. foram: no grupo A, 3,5; grupo B, 1,2; grupo C, 1. A diferença entre o resultado do grupo A com os resultados dos grupos B e C foi considerada estatisticamente significativa (P < 0,05). CONCLUSÃO: O pré e pós-condicionamento isquêmico foram capazes de minimizar, com intensidade semelhante, a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.

OBJECTIVE: To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure. METHODS: Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed. RESULTS: According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05). CONCLUSION: Ischemic pre- and postconditioning were capable of minimizing - in a similar intensity - the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process.

Tratamento da isquemia mesentérica pelo pós-condicionamento isquêmico / Mesenteric ischemia's treatment by postconditioning

Sabe-se que o pré-condicionamento isquêmico tem a capacidade de minimizar as lesões decorrentes do processo de isquemia e reperfusão. Recentemente foi descrito que o pós-condicionamento isquêmico apresenta resultados semelhantes em isquemia e reperfusão miocárdica, cerebral, renal e da medula espinhal, mas não há relatos de utilização deste método na isquemia mesentérica. OBJETIVO: O objetivo deste estudo é avaliar o efeito do pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. MÉTODO: Foram estudados 20 ratos Wistar, distribuídos em dois grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu e procedeu-se o tratamento estatístico. RESULTADO: As médias dos graus de lesão tecidual foram: grupo A, 3,5; grupo B, 1. A diferença entre os grupos foi considerada estatisticamente significativa (p < 0,05). CONCLUSÃO: Concluiu-se que o pós-condicionamento isquêmico foi capaz de minimizar a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.

It is known that the preconditioning has the capacity to minimize the current lesions of the ischemia and reperfusion process. Recently it was described that the postconditioning presents similar results in miocardic ischemia and reperfusion, brain, kidneys and of the spinal cord, but there are no reports of use of this method in the mesenteric ischemia. OBJECTIVE: The objective of this study is to evaluate the effect of the postconditioning on the tissue lesion in the intestinal mucosa of rats submitted to the ischemia and reperfusion process. METHOD: 20 Wistar rats were studied, distributed in two groups: group A, in that was done mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion and, preceding the beginning of the reperfusion, the postconditioning was accomplished. At the end, it was dried up a segment of the small intestine for histological analysis. The results were evaluated by the Chiu's classification and the statistical treatment was proceeded. RESULTS: The averages of the degrees of tissue lesion were: group A, 3,5; group B, 1. The difference between the groups was statistically significant (p <0,05). CONCLUSION: The postconditioning was capable to minimize the tissue lesion in the intestinal mucosa of rats submitted to the mesenteric ischemia and reperfusion process.

Osteossarcomas humanos de alto grau: imunoexpressão de p53, erb-2 e P-glicoproteína, e correlação com o parâmetro anaplasia / P-glycoprotein, erb2 and p53 expression in high-grade human osteosarcomas and their correlation with anaplasia

INTRODUÇÃO: Osteossarcoma (OS), o mais freqüente tumor primário maligno do osso, tem comportamento local agressivo e alto índice de disseminação sistêmica. Os eventos que permitem o crescimento e a disseminação tumoral ainda permanecem controversos. Os estudos sobre a carcinogênese e a progressão dessa neoplasia, com base na imunoexpressão de c-erb-B2, P-glicoproteína (P-gp) e p53, apresentam resultados conflitantes acerca do real valor prognóstico e suas correlações com parâmetros histológicos. A anaplasia, em neoplasias na infância, constitui parâmetro histológico de agressividade tumoral e quimiorresistência. Nos OS primários ou metastáticos, seu significado permanece controverso. Por outro lado, em outras neoplasias humanas, a expressão do c-erb-B2 relaciona-se com p53, grau nuclear e outros parâmetros de agressividade. OBJETIVO: Avaliar a imunoexpressão de p53, c-erb-B2 e P-gp em OS, correlacionando os parâmetros entre si e com a presença de anaplasia. MÉTODO: O estudo incluiu 96 biópsias pré-quimioterapia de pacientes com OS de alto grau, diagnosticados entre 1991 e 2000. A pesquisa imuno-histoquímica de p53, P-gp e c-erb-B2 foi feita pela técnica da estreptoavidina-biotina-peroxidase. Foram considerados positivos os casos onde havia imunoexpressão em 10 por cento ou mais das células neoplásicas. Somente colorações membranosa (para cerb-B2 e P-gp) e nuclear (para p53) foram consideradas positivas. Anaplasia foi definida como no tumor de Wilms, sendo considerada presente ou ausente. RESULTADOS: Anaplasia pôde ser avaliada em 82/96 casos, estando presente em 29 (35,36 por cento). Imunoexpressão de p53 foi detectada em 25 dos 60 casos (36,23 por cento); de P-gp, em 30 dos 73 casos (41,1 por cento); e de c-erb-B2, em 22 dos 55 casos (40 por cento). Os resultados demonstraram associação entre as imunoexpressões de c-erb-B2 e p53 (p = 0,042), p53 e o parâmetro anaplasia (p = 0,015), anaplasia e Pg (p = 0.034) CONCLUSÕES: A imunoexpressão...

BACKGROUND: Osteosarcomas (OS), the most frequent primary malignant bone tumors, have aggressive local behavior and high rate of metastatization. The events that allow tumor growth and dissemination are still controversial. The studies about carcinogenesis and tumor progression in this neoplasia, which are based on c-erb-B2, P-glycoprotein (P-gp) and p53 immunoexpression, show conflicting results as to the real prognostic value and its correlations with histological parameters. Anaplasia in childhood neoplasias is a histological parameter of tumor aggressiveness and chemoresistance. In primary or metastatic OS, its meaning remains controversial. On the other hand, in other human neoplasias, c-erb-B2 expression is associated with p53, nuclear grade and other aggressiveness parameters. OBJECTIVE: The aim of the present study was to evaluate p53, c-erb-B2 and P-gp immunoexpression in OS, correlating the parameters with the presence of anaplasia. METHODS: This study included 96 pre-chemotherapy biopsies in patients with high-grade OS diagnosed between 1991 and 2000. The immunohistochemical evaluation of p53 and c-erb-B2 was carried out with the streptavidin-biotin-peroxidase technique. Cases were considered positive when there was immunoexpression in 10 percent or more neoplastic cells. Only membrane staining (for c-erb-B2 and P-gp), and nuclear staining (for p53) were considered positive. Anaplasia was defined as Wilms' tumor, and considered present or absent. RESULTS: Anaplasia was present in 29 out of 82 cases (35.36 percent); p53 immunoexpression was detected in 25 out of 60 cases (36.23 percent); P-gp, in 30 out of 73 cases (41.1 percent); and c-erb-B2, in 22 out of 55 cases (40 percent). The results demonstrated an association between c-erb-B2 and p53 immunoexpression (p = 0.042), p53 and parameter of anaplasia (p = 0.015), anaplasia and P-gp (p = 0.034). CONCLUSIONS: The p53, c-erb-B2 and P-gp immunoexpression is relatively frequent in high-grade, metastic...

The ischemic preconditioning and postconditioning effect on the intestinal mucosa of rats undergoing mesenteric ischemia/reperfusion procedure.

PURPOSE: To evaluate the effect of the ischemic preconditioning and the ischemic postconditioning over the tissue injury in the intestinal mucosa of rats undergoing the procedure of mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were studied, divided in three groups: group A, undergoing mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion preceded by ischemic preconditioning; group C, mesenteric ischemia and reperfusion and, before the beginning of reperfusion, the ischemic postconditioning was performed. At the end, a segment of the small intestine was dissected for histological analysis. The results were evaluated using the CHIU et al.6 classification followed by the statistic treatment. RESULTS: The mean values of the tissue injury levels were: group A, 3.5; group B, 1.2; and group C, 1. The difference between the result of group A with the results of groups B and C was considered statistically significant (p < 0,05). CONCLUSION: The ischemic preconditioning and postconditioning are able to minimize the tissue injury in the intestines of rats that underwent the procedure of mesenteric ischemia and reperfusion.

The ischemic preconditioning and postconditioning effect on the intestinal mucosa of rats undergoing mesenteric ischemia/reperfusion procedure

PURPOSE: To evaluate the effect of the ischemic preconditioning and the ischemic postconditioning over the tissue injury in the intestinal mucosa of rats undergoing the procedure of mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were studied, divided in three groups: group A, undergoing mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion preceded by ischemic preconditioning; group C, mesenteric ischemia and reperfusion and, before the beginning of reperfusion, the ischemic postconditioning was performed. At the end, a segment of the small intestine was dissected for histological analysis. The results were evaluated using the CHIU et al.6 classification followed by the statistic treatment. RESULTS: The mean values of the tissue injury levels were: group A, 3.5; group B, 1.2; and group C, 1. The difference between the result of group A with the results of groups B and C was considered statistically significant (p < 0,05). CONCLUSION: The ischemic preconditioning and postconditioning are able to minimize the tissue injury in the intestines of rats that underwent the procedure of mesenteric ischemia and reperfusion.

OBJETIVO: Avaliar o efeito do pré e pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. MÉTODOS: Foram estudados 30 ratos Wistar, distribuídos em três grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica precedidos pelo pré-condicionamento isquêmico; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de CHIU e col.6 e procedeu-se o tratamento estatístico. RESULTADOS: As médias dos graus de lesão tecidual foram: grupo A, 3,5; grupo B, 1,2; grupo C, 1. A diferença entre o resultado do grupo A com os resultados dos grupos B e C foi considerada estatisticamente significativa (p < 0,05). CONCLUSÃO: O pré e pós-condicionamento isquêmico foram capazes de minimizar a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.