Remote ischemic conditioning enhances heart and brain antioxidant defense / Condicionamento isquêmico remoto melhora a defesa antioxidante do coração e do cérebro

Abstract Background Ischemia-reperfusion injury contributes to morbidity after revascularization procedures. Along with early reperfusion, tissue conditioning by alternating intervals of brief ischemia-reperfusion episodes is considered the best approach to limit tissue damage. Remote ischemic conditioning is conducted remotely, in tissues other than those under ischemia. Despite this, remote ischemic conditioning protection mechanisms are poorly understood, which can lead to misapplication. Objectives To assess whether remote ischemic conditioning works in the heart and brain through enhancement of cells' antioxidant defenses and whether the response is sustained or temporary. Methods Twenty-one male Wistar rats were assigned to three groups (n = 7): SHAM: same procedure as the other groups, but no remote ischemic conditioning was carried out. RIC 10: heart and brain were harvested 10 minutes after the remote ischemic conditioning protocol. RIC 60: heart and brain were harvested 60 minutes after the remote ischemic conditioning protocol. The remote ischemic conditioning protocol consisted of 3 cycles of 5 min left hindlimb ischemia followed by 5 min left hindlimb perfusion, lasting 30 min in total. Heart and brain samples were used to measure the tissue antioxidant capacity. Results Remote ischemic conditioning increased heart and brain antioxidant capacity after 10 minutes (0.746 ± 0.160/0.801 ± 0.227 mM/L) when compared to SHAM (0.523 ± 0.078/0.404 ± 0.124 mM/L). No enhancement of heart or brain antioxidant capacity was detected 60 minutes after remote ischemic conditioning (0.551 ± 0.073/0.455 ± 0.107 mM/L). Conclusions Remote ischemic conditioning temporarily enhances heart and brain antioxidant defenses in male Wistar rats.

Resumo Contexto A lesão de isquemia e reperfusão contribui para a morbidade após procedimentos de revascularização. Juntamente com a reperfusão precoce, o condicionamento tecidual através de breves episódios de isquemia e reperfusão é considerado a melhor abordagem para limitar o dano tecidual. Apesar disso, os mecanismos do condicionamento isquêmico remoto são pouco compreendidos, o que pode levar a uma aplicação incorreta. Objetivos Avaliar se o condicionamento isquêmico remoto funciona no coração e no cérebro através do aprimoramento da defesa antioxidante das células e se é uma resposta sustentada ou temporária. Métodos Vinte e um ratos Wistar foram divididos em três grupos (n = 7): SHAM, no qual não foi realizado condicionamento isquêmico; RIC 10, no qual 10 minutos após o protocolo de condicionamento isquêmico, foi realizada a coleta dos órgãos; e RIC 60, no qual 60 minutos após o protocolo de condicionamento isquêmico, foi realizada a coleta dos órgãos. O protocolo de condicionamento isquêmico remoto consistiu em três ciclos de 5 minutos de isquemia, seguidos de 5 minutos de perfusão no membro posterior esquerdo, com duração total de 30 minutos. Amostras foram usadas para medir a capacidade antioxidante do tecido. Resultados O condicionamento isquêmico remoto aumentou a capacidade antioxidante do coração e do cérebro após 10 minutos (0,746 ± 0,160/0,801 ± 0,227 mM/L) quando comparado ao SHAM (0,523 ± 0,078/0,404 ± 0,124 mM/L) . Sessenta minutos após o condicionamento isquêmico remoto, não foi detectado aumento da capacidade antioxidante do coração ou do cérebro (0,551 ± 0,073/0,455 ± 0,107 mM/L). Conclusões O condicionamento isquêmico remoto melhora temporariamente as defesas antioxidantes do coração e do cérebro em ratos Wistar.

Does the type of electrode affect the electromyoneurographic parameters in rats?

Abstract Purpose: To evaluate if the type of electrode (needle vs. surface) affects the electromyoneurography parameters in rats. Methods: Twenty male rats were anesthetized, then compound muscle action potential were recorded using a Neuropack S1 MEB- 9400©. All animals were submitted to two electroneuromyography analysis: first with surface electrode and then by needle electrode. We evaluated the latency, amplitude, duration and area of the negative peak of the gastrocnemius and cranial tibial muscles. Results: There were no significant differences between the groups in the mean of duration, latency, amplitude or area of the negative peak in gastrocnemius and cranial tibial muscles. Conclusion: The type of electrode does not affect the electroneuromyography parameters.

Modelo de dissecção e acesso vascular de baixo custo / Low cost model for vascular dissection and access

OBJETIVO: Descrever um modelo de treinamento de baixo custo de dissecção e acesso vascular utilizando língua bovina. MÉTODOS: Foram utilizadas dez línguas de boi para confecção de simuladores. Inicialmente, o corpo da língua foi dissecado, separando as camadas epitelial e muscular, e o pedículo vascular foi destacado da base da língua. A artéria principal da língua foi, então, cateterizada e conectada a uma seringa, sendo, em seguida, fixada à porção muscular. Após, para simular o tecido celular subcutâneo, foi confeccionada uma pasta amarela gelatinosa, que foi posicionada de modo a cobrir a extensão do pedículo vascular por inteiro. Por fim, a camada epitelial da língua foi reposicionada sob a camada muscular, por meio de sutura contínua. Para avaliar o modelo, foram observados o tempo de confecção do modelo, sua durabilidade, seu custo e o número de vezes que pôde ser usado. RESULTADOS: O tempo médio para confecção do modelo foi de 15,82±2,45 minutos, com durabilidade de 20 dias sob refrigeração. O custo médio foi de R$25,00, podendo ser utilizado, em média, por 3,8±0,63 vezes. Não houve falhas na montagem do modelo. CONCLUSÃO: O modelo de língua de boi se mostrou viável e de fácil aplicação para o treinamento de técnica cirúrgica de dissecção vascular. (AU)

OBJECTIVE: To describe a low cost training model for dissection and vascular access using a bovine tongue. METHODS: Ten bovine tongues were used to build simulators. First, the body of the tongue was dissected, with its epithelial layer being separated from the muscular layer, and the vascular pedicle was detached from the base of the tongue. The tongue main artery was then catheterized and connected to a syringe, and subsequently fixed to the muscle layer. Then, the entire vascular pedicle was covered with a yellow gelatinous paste to simulate the subcutaneous tissue. Finally, the epithelial layer was repositioned above the muscle layer through continuous suture. To evaluate the model, 4 variables were considered: 1) time for building the model, 2) its durability, 3) its cost, 4) number of times that it could be used. RESULTS: The mean time to make the model was 15.82 ±2.45 minutes, with a durability of 20 days under refrigeration. The mean cost of each model was U$10.00, and could be used about 3.8±0.63 times. There were no fails to build the model. CONCLUSIONS: The model with a bovine tongue proved to be viable and easy to be applied for training the surgical technique of vascular dissection. (AU)

Influence of oophorectomy on glycemia and lipidogram

Abstract Purpose: To verify the influence of oophorectomy on lipidogram and glycemia. Methods: Fifty six female rats were divided into the following 7 groups (n = 8): group 1 - sham group, group 2 - oophorectomy 30 days, group 3 - oophorectomy 35 days, group 4 - oophorectomy 40 days, group 5 - oophorectomy 45 days, group 6 - oophorectomy 70 days, group 7 - oophorectomy 55 days. Animals were following by number of days according the group. Was evaluated the serum levels of glucose and lipid profile. Results: The oophorectomized rats presented higher glycemia. Groups 3, 4, 6 and 7 had a higher glycemia and LDL levels (except for group 6) and groups 6 and 7 had lowest levels of HDL. Group 7 had highest level of VLDL than oophorectomy groups. There was no difference in triglycerides levels. Conclusion: Oophorectomy was related to dyslipidemia and insulin resistance, mainly after 50th days.

Continuous versus interrupted suture technique in microvascular anastomosis in rats

Abstract Purpose: To compare the continuous and interrupted suture technique on femoral artery on rats after vessel repair and 14 days after. Methods: Twenty rats were operated randomly divided into two group matched according to the suture technique used: interrupted or continuous. We performed a femoral anastomosis on the right femoral artery. We analyzed weight, arterial caliber, anastomosis time and patency after vessel repair and 14 days after. Results: There was no significant difference between groups in the weight (p=0.64), diameter of the femoral artery (p=0.95) and patency (p=1.00). The time spent in the anastomosis was 451 seconds in the continuous group and 718 seconds in the interrupted group, presenting significant difference (p<0.01). Conclusion: The continuous suture technique shows a similar patency rates than interrupted technique, however with a shorter time to perform the anastomosis.

Perconditioning combined with postconditioning on kidney ischemia and reperfusion

Abstract Purpose: To evaluate if combination of perconditioning and postconditioning provides improved renal protection compared to perconditioning alone in a model of renal reperfusion injury. Methods: Thirty rats were assigned into 6 groups: normality; sham; ischemia and reperfusion; postconditioning; perconditioning; perconditioning + postconditioning. Animals were subjected to right nephrectomy and left renal ischemia for 30 minutes. Postconditioning consisted of 3 cycles of 5 min renal perfusion followed by 5 min of renal ischemia after major ischemic period. Perconditioning consisted of 3 cycles of 5 min hindlimb ischemia followed by 5 min of hindlimb perfusion contemporaneously to renal major ischemic period. After 24 hours, kidney was harvested and blood collected to measure urea and creatinine. Results: Perconditioning obtained better values for creatinine and urea level than only postconditioning (p<0.01); performing both techniques contemporaneously had no increased results (p>0.05). Regarding tissue structure, perconditioning was the only technique to protect the glomerulus and tubules (p<0.05), while postconditioning protected only the glomerulus (p<0.05). Combination of both techniques shows no effect on glomerulus or tubules (p>0.05). Conclusions: Perconditioning had promising results on ischemia and reperfusion induced kidney injury, enhanced kidney function and protected glomerulus and tubules. There was no additive protection when postconditioning and perconditioning were combined.

Treinamento de anastomoses vasculares de baixo custo: o cirurgião vai à feira / Vascular anastomoses are common procedures and are performed by most surgeons. Training is primarily conducted in human beings, which violates current ethical principles. This is because current training models are expensive and in short supply. This study was designed to investigate the feasibility of three vegetable models of vascular anastomosis. Five units each of scallions, green beans, and yardlong beans were used. An end-to-end anastomosis was attempted with each specimen. Anastomoses were only successful in green beans and yardlong beans. Since they are narrower, the yardlong beans are the most similar to human vessels

Anastomoses vasculares são procedimentos comuns realizados por grande parte dos cirurgiões e cujo treinamento ocorre principalmente em seres humanos, contrariando os princípios éticos vigentes. Esse fato se deve, sobretudo, à carência e ao alto custo relacionados aos atuais modelos de treinamento. Assim, este estudo visa avaliar a viabilidade de três vegetais para a realização de anastomoses vasculares. Foram utilizadas cinco unidades de cebolinha, vagem e feijão-verde. Em cada uma tentou-se realizar uma anastomose término-terminal. Conseguiu-se a realização da anastomose apenas na vagem e no feijão-verde. Contudo, por apresentar uma menor espessura, o feijão-verde assemelhou-se mais aos vasos humanos

Vascular anastomoses are common procedures and are performed by most surgeons. Training is primarily conducted in human beings, which violates current ethical principles. This is because current training models are expensive and in short supply. This study was designed to investigate the feasibility of three vegetable models of vascular anastomosis. Five units each of scallions, green beans, and yardlong beans were used. An end-to-end anastomosis was attempted with each specimen. Anastomoses were only successful in green beans and yardlong beans. Since they are narrower, the yardlong beans are the most similar to human vessels

Morphometric analysis of rat femoral vessels under a video magnification system / Análise morfométrica dos vasos femorais de ratos sob magnificação por sistema de vídeo

The right femoral vessels of 80 rats were identified and dissected. External lengths and diameters of femoral arteries and femoral veins were measured using either a microscope or a video magnification system. Findings were correlated to animals' weights. Mean length was 14.33 mm for both femoral arteries and femoral veins, mean diameter of arteries was 0.65 mm and diameter of veins was 0.81 mm. In our sample, rats' body weights were only correlated with the diameter of their femoral veins

Os vasos femorais de 80 ratos foram identificados e dissecados. O comprimento e o diâmetro externo da artéria e da veia femoral foram mensurados com o auxílio de um microscópio e um sistema de magnificação por vídeo. Esses parâmetros foram correlacionados com o peso do animal. O comprimento de ambos os vasos femorais foi de 14,33 mm, e a média do diâmetro das artérias foi de 0,65 mm, e das veias, de 0,81 mm. Na nossa amostra, o peso dos animais se correlacionou apenas com o diâmetro da veia femoral

Stem cells from adipose tissue improve the time of wound healing in rats

ABSTRACT PURPOSE: To evaluate the Adipose Stem Cells (ACS) therapy efficacy on the time and quality of wound healing process in rats. METHODS: Nine male Wistar rats were randomly distributed into three groups I) 7 days of healing; II) 14 days of healing; III) 21 days of healing. Four incisions were made on the dorsal surface of each rat and then treated with intralesional ACS, meloxicam, and no treatment and ACS+meloxicam. Macroscopic evaluation was measured by percentage of healing and histopathological by hematoxylin-eosin was performed. RESULTS: All groups have the wound reduced during the three weeks (p<0.001) and after 14 days of healing had greater reduction than others. Wounds treated with ASC had accelerated healing in relation to no treatment and only meloxicam (p<0.001), excepting the ASC+Meloxicam that was similar (p=0.13). There was no difference in histopathological analysis between lesions. CONCLUSION: Adipose stem cell have benefits in reducing time of healing of experimental model of wound in rats, observed 7 days of after application.