Remote ischemic conditioning improves rat brain antioxidant defense in a time-dependent mechanism.

PURPOSE: To clarify the best protocol for performing remote ischemic conditioning and to minimize the consequences of ischemia and reperfusion syndrome in brain, the present study aimed to evaluate different time protocols and the relation of the organs and the antioxidant effects of this technique. METHODS: The rat's left femoral artery was clamped with a microvascular clamp in times that ranged from 1 to 5 minutes, according to the corresponding group. After the cycles of remote ischemic conditioning and a reperfusion of 20 minutes, the brain and the left gastrocnemius were collected. The samples were used to measure glutathione peroxidase, glutathione reductase and catalase levels. RESULTS: In the gastrocnemius, the 4-minute protocol increased the catalase concentration compared to the 1-minute protocol, but the latter increased both glutathione peroxidase and glutathione reductase compared to the former. On the other hand, the brain demonstrated higher catalase and glutathione peroxidase in 5-minute group, and the 3-minute group reached higher values of glutathione reductase. CONCLUSIONS: Remote ischemic conditioning increases brain antioxidant capacity in a time-dependent way, while muscle presents higher protection on 1-minute cycles and tends to decrease its defence with longer cycles of intermittent occlusions of the femoral artery.

Comparison of remote and local postconditioning against hepatic ischemic-reperfusion injury in rats.

PURPOSE: The aim of this study is to compare the hepatic protective effect of both remote and local postconditioning (POS). METHODS: Twenty-eight Wistar rats were assigned into four groups: sham group(SHAM), ischemia-reperfusion group (IR), local ischemic POS group (lPOS) and remote ischemic POS group (rPOS). Animals were subjected to liver ischemia for 30 min. Local ischemic POS group consisted of four cycles of 5 min liver ischemia, followed by 5 min reperfusion (40 min). Remote ischemic POS group consisted of four cycles of 5 min hind limb ischemia, followed by 5 min hind limb perfusion after the main liver ischemia period. After 190 minutes median and left liver lobes were harvested for biochemical and histopathology analysis. RESULTS: All the conditioning techniques were able to increase the level of bothglutathione reductase and peroxidase, showing higher values in the rPOS group when compared to the lPOS. Also, thiobarbituric acid reactive substances were higher in all intervention groups when compared to SHAM, but rPOS had the lower rates of increase, showing the best result. The histopathology analysis showed that all groups had worst injury levels than SHAM, but rPOS had lower degrees of damage when compared to the lPOS, although it was not statistically significant. CONCLUSION: Remote postconditioning is a promising technique to reduce liver ischemia-reperfusion injury, once it increased antioxidants substances and reduced the damage.

Generalized anxiety disorder and prevalence of suicide risk among medical students / Prevalência do transtorno de ansiedade generalizada e do risco de suicídio em estudantes de medicina

Abstract: Introduction: Generalized anxiety disorder (GAD) is a common pathology in modern life. Furthermore, Brazil ranks among one of the countries in Latin America with the highest increase in the number of suicides. Objective: The goal of this study is to evaluate the prevalence of GAD and suicide risk and their association in medical students from Belém - PA. Methods: The observational, cross-sectional and quantitative study included undergraduate medical students attending the 1st, 3rd and 5th years of Universidade do Estado do Pará as subjects of this research, totaling 153 students. It used a protocol created by the authors and the Mini International Neuropsychiatric Interview. The software BioEstat® 5.3 was used to perform the statistical analysis. Results: 52 (32,7%) of the 159 students have GAD and 48 (30,2%) pose a suicide risk, of which 18 have a mild risk (11,3%), 17 a moderate risk (10,7%) and 13 a high risk (8,2%). 46,7% and 50% of the 1st and 3rd-year students, respectively, have higher risk of suicide, which could be related to the competition faced during the University admission process and also during the first years of the clinical cycle. Of the 5th year students who pose a suicide risk, only 21,7% have high risk. Conclusion: It can be observed that GAD and suicide risk show high prevalence among medical students, which has to be investigated and treated aiming to reduce the impacts of those disorders on health professionals and students.

Resumo: Introdução: O transtorno de ansiedade generalizada (TAG) é uma patologia comum da modernidade. Além disso, o Brasil figura entre um dos países da América Latina com o maior aumento do número de suicídios. Objetivo: Este estudo teve como objetivo avaliar a prevalência de TAG e risco de suicídio e a associação entre eles em estudantes de Medicina de Belém, no Pará. Métodos: O estudo observacional, transversal e quantitativo teve como sujeitos da pesquisa graduandos do curso de Medicina que estavam matriculados no primeiro, terceiro e quinto anos na Universidade do Estado do Pará, totalizando 159. Utilizaram-se questionário de autoria dos pesquisadores e o Mini International Neurophsychiatric Interview, sendo a análise estatística feita com o software BioEstat® 5.3. Resultados: Dos 159 estudantes, 52 (32,7%) apresentaram TAG; e 48 (30,2%), risco de suicídio, dos quais 18 tiveram risco leve (11,3%); 17, risco moderado (10,7%); e 13, risco elevado (8,2%). Dos alunos, 46,7% e 50%, respectivamente do primeiro e terceiro anos, apresentaram risco elevado de suicídio, fato que pode estar associado com a pressão do vestibular e do início do ciclo clínico. Dos alunos do quinto ano com risco de suicídio, somente 21,7% apresentaram risco elevado. Conclusão: Percebe-se uma importante taxa de TAG e de risco de suicídio entre os estudantes de Medicina, o que precisa ser investigado e trabalhado para minimizar os impactos desses transtornos nos discentes.

Remote ischemic conditioning improves rat brain antioxidant defense in a time-dependent mechanism

ABSTRACT Purpose To clarify the best protocol for performing remote ischemic conditioning and to minimize the consequences of ischemia and reperfusion syndrome in brain, the present study aimed to evaluate different time protocols and the relation of the organs and the antioxidant effects of this technique. Methods The rat's left femoral artery was clamped with a microvascular clamp in times that ranged from 1 to 5 minutes, according to the corresponding group. After the cycles of remote ischemic conditioning and a reperfusion of 20 minutes, the brain and the left gastrocnemius were collected. The samples were used to measure glutathione peroxidase, glutathione reductase and catalase levels. Results In the gastrocnemius, the 4-minute protocol increased the catalase concentration compared to the 1-minute protocol, but the latter increased both glutathione peroxidase and glutathione reductase compared to the former. On the other hand, the brain demonstrated higher catalase and glutathione peroxidase in 5-minute group, and the 3-minute group reached higher values of glutathione reductase. Conclusions Remote ischemic conditioning increases brain antioxidant capacity in a time-dependent way, while muscle presents higher protection on 1-minute cycles and tends to decrease its defence with longer cycles of intermittent occlusions of the femoral artery.