The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury

Abstract Purpose: To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC). Methods: Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes. Results: The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation. Conclusion: The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.

The role of atenolol in the modulation of the expression of genes encoding pro- (caspase-1) and anti- (Bcl2L1) apoptotic proteins in endothelial cells exposed to intestinal ischemia and reperfusion in rats

Abstract Purpose: To investigate the role of atenolol in the gene expression of caspase 1 (Casp1) and Bcl2L1 on vascular endothelium of rat intestine after ischemia and reperfusion (IR). Methods: Eighteen adult male Wistar rats were randomly divided into 3 groups (n=6): SG (Sham group): no clamping of the superior mesenteric artery; IRG: IR plus saline group: IRG+At: IR plus Atenolol group. Rats from IRG and IRG+At were subjected to 60 min of intestinal ischemia and 120 min of reperfusion. Atenolol (2mg/kg) or saline were injected in the femoral vein 5 min before ischemia, 5 min and 55 min after reperfusion. Thereafter, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. Results: the anti-apoptotic Bcl2L1 gene expression was significantly down-regulated (-1.10) in the IRG and significantly up-regulated in the IRG+At (+14.15). Meanwhile, despite Casp1 gene expression was upregulated in both groups, it was significantly higher in the IRG (+35.06) than the IRG+At (+6.68). Conclusions: Atenolol presents antiapoptotic effects on rat intestine subjected to IR partly by the up-regulation of the anti-apoptotic Bcl2L1 gene expression. Moreover, atenolol can mitigate the pro-apoptotic and pro-inflammatory effects of Casp1 gene on rat intestine after IR.

Different protocols of postconditioning does not attenuate mesenteric ischemia-reperfusion injury after short-term reperfusion / Diferentes protocolos de pós-condicionamento não atenua a lesão de isquemia e reperfusão mesentérica após curto período de reperfusão

ABSTRACT Background: Mesenteric ischemia is a challenging diagnosis. Delay in diagnosis can lead to extent bowel necrosis and poor outcomes. Ischemia and reperfusion syndrome plays an important role in this scenario. Aim: To access effects of different post-conditioning cycles on mesenteric ischemia-reperfusion syndrome. Method: Twenty-five rats were assigned into five groups: Sham, used to establish normal parameters; control group, submitted to mesenteric ischemia for 30 min; in groups GP3, GP1 and GP30, ischemia was followed by post-conditioning protocol, which consisted of 1 cycle of 3 min (GP3), 3 cycles of 1 min (GP1) or 6 cycles of 30 s (GP30), respectively. Ileum samples were harvested after one hour of reperfusion. Intestinal mucosal injury was evaluated through histopathological analysis. Results: The average of mesenteric injury degree was 0 in the sham group, 3.6 in the control group, 3.4 in GP3, 3.2 in GP1, and 3.0 in GP30; villous length average was 161.59 in sham group, 136.27 in control group, 135.89 in GP3, 129.46 in GP1, and 135.18 in GP30. Was found significant difference between sham and other groups (p<0.05); however, there was no difference among post-conditioning groups. Conclusion: Post-conditioning adopted protocols were not able to protect intestinal mucosa integrity after mesenteric ischemia and short term reperfusion.

RESUMO Racional: O desfecho satisfatório na abordagem cirúrgica da obesidade deve contemplar, além da perda de peso, alteração significativa nas comorbidades preexistentes e na qualidade de vida dos pacientes. Objetivo: Avaliar a qualidade de vida no pós-operatório tardio de pacientes submetidos à cirurgia de gastrectomia vertical por videolaparoscopia. Métodos: Foi aplicado o questionário "Bariatric Analysis and Reporting Outcome System" (BAROS) em pacientes submetidos à gastrectomia vertical por videolaparoscopia. Resultados: Foram avaliados 47 pacientes, entre 21 e 60 anos de idade. O IMC médio antes da operação era 43,06±5,87 kg/m². A média percentual de redução do excesso de peso após foi de 85,46±23,6%. A pontuação obtida pelos pacientes no questionário sobre a melhora na qualidade de vida evidenciou resultado excelente (36,17%), ótimo (40,43%), bom (21,28%) e razoável (2,13%). Houve melhora clínica após a operação em todas as comorbidades investigadas. Conclusão: A perda de peso foi fundamental para a melhoria na qualidade de vida e proporcionou resolução ou a melhora clínica em todas as comorbidades investigadas.

Formulation and evaluation of orally disintegrating clopidogrel tablets

ABSTRACT Recent advances in drug delivery systems have aimed to achieve better patient compliance. One of these advances is the formulation of orally disintegrating tablets (ODTs) that dissolve instantaneously, releasing drugs within a few seconds without the need of water. The main objective of this paper was to prepare and develop ODTs of clopidogrel. The ODTs were prepared by direct compression. The effect of three superdisintegrants, namely crospovidone, croscarmellose sodium, and sodium starch glycolate, using three different disintegration times on the dissolution rate was investigated. The prepared tablets were evaluated for hardness, friability, disintegration time and in vitro drug release. Furthermore, the interaction of clopidogrel with the formulation excipients was studied using differential scanning calorimetry (DSC). DSC studies revealed that there were no interactions between the drug and the excipients used. All tablets had hardness values in the range 4.0-5.2 kp and friability lower than 1%. The weight and drug content uniformity of all formulations was within official limits according to BP. In vitro drug release studies of the ODTs showed that more than 90% of the drug was released within ten minutes. A palatability test in human volunteers showed acceptable taste and mouth feel. Thus, the obtained results conclusively demonstrated successful rapid disintegration of the formulated tablets and acceptable palatability.

RESUMO Recentes avanC'os em sistemas de liberaC'C#o de fC!rmacos novos visam C obtenC'C#o de melhor adesC#o do paciente. Um destes avanC'os C) a formulaC'C#o de comprimidos de desintegraC'C#o oral (ODTs), que se dissolvem instantaneamente, liberando o fC!rmaco, em alguns segundos, sem a necessidade de C!gua. O principal objetivo deste trabalho foi preparar e desenvolver ODTs de clopidogrel. Os ODTs foram preparados pelo mC)todo de compressC#o direta. Estudou-se o efeito de vC!rias concentraC'C5es de diferentes agentes de desintegraC'C#o, tais como super-crospovidona, croscarmelose de sC3dio, glicolato de amido de sC3dio no tempo de desintegraC'C#o e velocidade de dissoluC'C#o. Os comprimidos preparados foram avaliados quanto C dureza, C friabilidade, ao tempo de desintegraC'C#o e C liberaC'C#o do fC!rmaco in vitro. AlC)m disso, estudou-se a interaC'C#o de clopidogrel com os excipientes de formulaC'C#o, utilizando calorimetria de varredura diferencial (DSC). Estudos de DSC revelaram nC#o haver interaC'C#o entre o fC!rmaco e os excipientes utilizados. Todos os comprimidos possuC-am dureza na faixa de 4,0-5,2 kp e a friabilidade inferior a 1%. A variaC'C#o de peso e o teor de fC!rmaco de todas as formulaC'C5es mostraram-se dentro do limite oficial, de acordo com a BP. O estudo de liberaC'C#o do fC!rmaco in vitro de comprimidos ODTs mostrou que mais de 90% do fC!rmaco foram liberados em10 minutos. O teste de palatabilidade em voluntC!rios humanos mostrou sabor e sensaC'C#o na boca aceitC!veis. Assim, os resultados obtidos demonstraram, conclusivamente, a rC!pida e bem-sucedida desintegraC'C#o dos comprimidos formulados e a palatabilidade aceitC!vel.

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.

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. .