Influence of galantamine in the inflammatory process and tissular lesions caused by Trypanosoma cruzi QM2 strain

Abstract INTRODUCTION: Trypanosoma cruzi infection triggers an inflammatory process with exacerbated production of cytokines that stimulate inflammatory and anti-inflammatory signals, including the efferent anti-inflammatory signal known as the anti-inflammatory cholinergic pathway. Thus, the use of anticholinesterase drugs, such as galantamine, could minimize the inflammatory process caused by this disease. METHODS For the study at 30, 60, and 90 days, 120 Swiss mice were divided into three groups. Each group was subdivided into four subgroups: uninfected/untreated (CTRL), uninfected/treated (GAL), infected/untreated (INF), and infected/treated (GAL/INF). The infected groups were inoculated intraperitoneally with 0.1 ml of mouse blood containing 5 × 104 trypomastigote forms of the T. cruzi QM2 strain. The galantamine-treated groups received 5 mg/kg of galantamine orally, through pipetting. From each subgroup, the parameters of parasitemia, histopathological analysis, butyrylcholinesterase activity (BuChE), and functional study of the colon were evaluated. RESULTS: BuChE performance was observed when AChE was suppressed, with increased activity in the GAL/INF group similar to the INF group on the 30th day post infection, thus corroborating the absence of a significant difference in parasitic curves and histopathological analysis. CONCLUSIONS: The presence of an inflammatory process and nests of amastigotes, as well as evidence of reactivity to ACh and NOR, suggest that galantamine did not interfere with the colonic inflammatory response or even in colonic tissue parasitism at this stage of Chagas disease.

Academic research challenges in Brazil and its impairment by COVID-19 pandemic: a medical students point of view / O impacto da pandêmica COVID-19 na iniciação científica brasileira: ponto de vista de estudantes de medicina

ABSTRACT: Background: The COVID-19 pandemic and its control measures, which have not been experienced in the world in the last hundred years, have impacted academic scientific production, which, in Brazil, was already in the process of progressive erosion of its foundations. Thus, scientific initiation during medical graduation, which depends on funding and institutional structure, and extremely beneficial to the graduation process, was jeopardized due to restrictive measures. Objective: This article aims to expose the point of view of undergraduate medical students enrolled in a scientific initiation program about the panorama of Brazilian academic scientific production and the impact of the COVID-19 pandemic in its multiple aspects. Discussion: The lack of an effective scientific initiation is one of the many factors that lead to a decline in the number of medical researchers. The way that scientific initiation is placed, as part of a parallel curriculum, and a whole scrapped public production structure are impairing, chronic and noteworthy features. The apparatus of national scientific production is mostly structured in Higher Education Institutions and research institutions, both public. Within the scope of graduation, it can be didactically subdivided into four pillars: financial support, structure, student proactivity and the advisor's aptitude. The COVID-19 pandemic has been an additional blow to this weakened and fragile structure. Scientific initiation was thus negatively impacted. Public opinion and political aspects further influence an imbroglio of "scientific denial" and a craving for effective information and solutions to the unprecedented problem of a pandemic of this proportion. Conclusion: It is clear that national scientific production is placed in a survival situation in the face of new challenges posed by the pandemic. Likewise, scientific initiation is less and less stimulating during graduation, even though it is an experience of great value in medical and personal development. (AU)

RESUMO: Introdução: A pandemia pelo COVID-19 e suas medidas de controle, não vivenciadas no mundo nos últimos cem anos, impactou a produção científica acadêmica, a qual, no Brasil, já se encontrava em processo de erosão progressiva de seus alicerces. Por conseguinte, a iniciação científica durante a graduação, extremamente benéfica na formação médica, que é dependente de fomento e estrutura institucional, sofreu um impacto negativo com as medidas restritivas. Objetivo: O artigo discorre em um ponto de vista de estudantes de medicina, envolvidos em pesquisas, acerca do panorama da produção científica acadêmica brasileira e o impacto perante a pandemia COVID-19 em seus múltiplos aspectos. Discussão: A falta de uma iniciação científica efetiva é um dos muitos fatores que levam ao declínio do número de médicos pesquisadores. Nesse ínterim, o modo como a iniciação científica está inserida, como parte de um currículo paralelo, e toda uma estrutura de produção pública sucateada são aspectos danosos, crônicos e dignos de nota. O aparato de produção científica nacional é majoritariamente estruturado nas instituições de ensino superior e institutos de pesquisa, ambas públicas. No âmbito da graduação, pode ser didaticamente subdividido em quatro pilares: fomento, estrutura, proatividade do estudante e aptidão do orientador. A pandemia do COVID-19 tem sido um golpe adicional a essa estrutura debilitada e frágil. A iniciação científica foi, com isso, negativamente impactada. A opinião pública e aspectos políticos influenciam adicionalmente em um imbróglio de "negacionismo científico" e anseio por informações e soluções eficazes para o problema inédito de uma pandemia dessa proporção. Conclusão: Percebe-se que produção científica nacional é colocada numa situação de sobrevivência diante de novos desafios postos pela pandemia. Da mesma forma, a iniciação científica é cada vez menos estimuladora durante a graduação, apesar de ser uma experiência de grande valor na formação médica e pessoal. (AU)

Plasma antioxidant substances apparently do not influence the radiodermatitis occurrence / Substâncias antioxidantes do plasma aparentemente não influenciam a ocorrência de radiodermatite

AIMS: Radiation affects not only tumors but also healthy tissues through the increment of oxidative stress. Thus, this study aimed to evaluate the oxidative stress degree as well as non-enzymatic antioxidant defenses in the plasma of patients submitted to radiotherapy and to verify if these parameters are modified in those patients who develop radiodermatitis. METHODS: Forty-one patients submitted to radiotherapy for treatment of breast cancer were followed. From these patients, plasma samples were obtained at the beginning, in the middle and at the end of the treatment, for analysis of thiobarbituric acid reactive substances (TBARS) and ferric reducing ability of plasma (FRAP). RESULTS: No significant differences were observed in terms of TBARS and FRAP in plasma harvested from these patients at the beginning and at the middle of the treatment. There was lower incidence of grade two radiodermatitis among patients undergoing radiotherapy with hypofractionated doses. There were no differences in FRAP or TBARS among patients who developed radiodermatitis of any degree in relation to those who did not develop this side effect. No differences of FRAP or TBARS were observed between patients that presented grade two radiodermatitis regarding to the others studied. CONCLUSION: There was no clear relationship between changes in TBARS or FRAP with the occurrence or severity of radiodermatitis.

Oxidative stress among informal caregivers / Estresse oxidativo em cuidadores informais

ABSTRACT OBJETIVE: to evaluate oxidative stress and non-enzymatic antioxidant defenses in informal caregivers, and correlations with anxiety, health satisfaction and quality of life. METHOD: a case-control analytical study was performed, where the case was represented by the main informal caregiver and the control was paired with individuals with identical characteristics to the case, but who were not informal caregivers. The following instruments were used: a sociodemographic questionnaire, the Beck anxiety scale and the WHOQoL-Bref. Oxidative stress was measured through blood by analysis of the Ferric Reducing Ability of Plasma (FRAP) and Thiobarbituric Acid Reactive Substances (TBARS) markets. RESULTS: most informal caregivers were females. There was no difference in the degree of anxiety between the Case and Control groups. Among informal caregivers, 9.4% said they were very dissatisfied and 53.1% dissatisfied with their health. Most caregivers (43.8%) rated their quality of life as poor and 12.5% ​​as very poor, while most controls rated it as good (68.8%). The TBARS and FRAP values ​​were lower in the Case group than in the Control group. CONCLUSION: The informal caregivers, who were mostly women, defined themselves as dissatisfied or very dissatisfied with their health. Nevertheless, they did not manifest a higher degree of anxiety in comparison with the control population. In addition, they presented a lower degree of oxidative stress than the non-caregiving participants, perhaps due to a greater mobilization of the non-enzymatic antioxidant defenses present in the body.

OBJETIVO: Avaliar o estresse oxidativo e as defesas antioxidantes não enzimáticas em cuidadores informais, comparando os dados obtidos com indivíduos não cuidadores, correlacionando ao grau de ansiedade, satisfação com a saúde e qualidade de vida. MÉTODO: Estudo analítico caso-controle, onde o caso é representado pelo cuidador informal principal e o controle é pareado por indivíduos com características idênticas ao caso, exceto pelo fato de não desempenhar o papel de cuidador informal. Instrumentos utilizados: questionário sociodemográfico, escala de ansiedade de Beck e WHOQOL-bref. O estresse oxidativo foi medido por meio do sangue, com marcadores Ferric Reducing Ability of Plasma (FRAP) e Thiobarbituric Acid Reactive Substances (TBARS). Resultados: O cuidador informal é representado em sua maioria por indivíduos do sexo feminino. Não houve diferença no grau de ansiedade entre os grupos caso e controle. Dentre os cuidadores informais, 9,4% disseram estar muito insatisfeitos e 53,1% insatisfeitos com sua saúde. Referente à qualidade de vida, a maioria dos cuidadores (43,8%) classificou como ruim e 12,5% como muito ruim, enquanto a maior parte dos controles a classificou como boa (68,8%). Os valores de TBARS e FRAP foram menores no grupo caso em relação ao grupo controle. CONCLUSÃO: O cuidador informal, em sua maioria mulheres, se definem insatisfeitos ou muito insatisfeitos com sua saúde. Apesar disso, não manifestaram grau de ansiedade maior em relação à população controle. Apresentaram grau de estresse oxidativo menor em relação aos participantes não cuidadores, talvez, devido a maior mobilização das defesas antioxidantes não enzimáticas presentes no organismo.

Rivastigmine prevents injury induced by ischemia and reperfusion in rat liver

Abstract Purpose: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver. Methods: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration. Blood was also harvested for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) determinations. Results: I/R promoted a significant increase of mitochondrial swelling in the studied animals. This increase of mitochondrial swelling was partially prevented by rivastigmine, but only if administered 50 minutes before ischemia. No significant modification of MDA, nitrite or nitrate tissue concentrations was observed in consequence of I/R, followed or not by rivastigmine treatments. In addition, I/R elevated both AST and ALT. These elevations of serum enzymes were not reversed by the different rivastigmine treatments. Conclusions: Rivastigmine administered 50 minutes before ischemia attenuates I/R-induced mitochondrial swelling, that indicates liver injury. This protective effect may be related to a greater stimulation of α7nAChR present in the Kupffer cells by the non-methabolized ACh, leading to an attenuation of I/R-induced inflammation.

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion / A ingestão prévia de castanha-do-brasil atenua a lesão renal induzida por isquemia e reperfusão

ABSTRACT Introduction: Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury. Objective: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress. Methods: Male Wistar rats were distributed into six groups (N=6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR) and maintained until animal sacrifice (48h after surgery). We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx. Results: Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx. Conclusion: Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

RESUMO Introdução: a lesão por isquemia-reperfusão (IR) resulta, entre outros fatores, de inflamação e estresse oxidativo. Devido às suas propriedades anti-inflamatórias e antioxidantes, a castanha-do-brasil (BN) pode atenuar a lesão renal causada por IR. Objetivo: O objetivo foi investigar se a ingestão prévia de BN reduz a lesão e a inflamação renal causadas por IR, melhorando a função renal e o estresse oxidativo. Métodos: Ratos Wistar machos foram distribuídos em seis grupos (N=6/grupo): SHAM (controle), SHAM tratado com 75 ou 150 mg de BN, IR, e IR tratado com 75 ou 150 mg de BN. O procedimento de IR consistiu na nefrectomia à direita e oclusão da artéria renal esquerda por 30 minutos. A castanha foi administrada diariamente e individualmente por sete dias antes da cirurgia (SHAM ou IR), e mantida até o sacrifício (48h pós-cirurgia). Os seguintes parâmetros foram avaliados: creatinina, ureia e fósforo plasmáticos; proteinúria, volume urinário e depuração de creatinina; TBARS e TEAC (capacidade antioxidante) plasmáticos; expressão renal de iNOS e nitrotirosina, e influxo de macrófagos. Resultados: O pré-tratamento com 75 mg de BN atenuou os parâmetros de função renal alterados pela IR, com elevação da depuração de creatinina e o volume urinário, redução da proteinúria, ureia e fósforo plasmáticos, e diminuição da expressão de iNOS, nitrotirosina e da infiltração de macrófagos. Conclusão: A ingestão de baixa quantidade de BN, previamente ao processo de IR, melhora a função renal pela inibição da infiltração de macrófagos e do estresse oxidativo.

Potential radioprotective effect of AT1 receptor antagonists against morphological and ultrastructural changes in the testes induced by ionizing radiation / Potencial efecto radioprotector de antagonistas del receptor AT1 contra los daños morfológicos y ultraestructurales en los testículos inducido por la radiación ionizante

Radiotherapy is a source of human exposure to ionizing radiation. This pure energy causes deleterious effects on tissues, which result from oxidative stress, a phenomenon in which there is the participation of the Renin-Angiotensin System (RAS). The male genital organs are extremely radiosensitive and the action of radiation in the testes can significantly affect spermatogenesis. In search of potential radioprotective for male genital system, this study investigated whether the AT1 receptor antagonists minimize radiation-induced damage to reproductive tissues, by decreasing oxidative stress. Male Wistar rats were divided into six groups: 0 Gray (Gy) (control), 5 Gy (single dose in the scrotal area), telmisartan, losartan, 5Gy+telmisartan and 5Gy+losartan. The treatment started the day after irradiation with losartan 34 mg/kg (two times/day) and telmisartan 12 mg/kg (one time/day) during 60 days. For ultrastructural analysis, the testis fragments were fixed in 2 % glutaraldehyde and 4 % paraformaldehyde in 0.1 M phosphate buffer, pH 7.3. The material was postfixed for 2 h in 1 % osmium tetroxide. For collagen evaluation, the sections were stained with Picrosirius-red method. Serum testosterone was determined. The date showed the deleterious effects of gamma radiation on testicular ultrastructure. Rich accumulation of collagen fibers in the interstitium was observed in the irradiated groups, especially the irradiated and nontreated testes. No significant difference was detected in serum testosterone concentration among the studied experimental groups. Treatments with telmisartan and losartan influenced the onset of attenuation on ultrastructural damages arising from ionizing radiation. Although the data strongly suggest that AT1 receptor antagonists may promote radioprotection to the testes, further studies with a longer duration of treatment are required for these potentially positive effects to be maximized and, therefore, to better characterize radioprotection to reproductive parameters.

El tratamiento radioterápico es una fuente de exposición del ser humano a la radiación ionizante. Esta energía pura causa efectos deletéreos en los tejidos, debido al estrés oxidativo, fenómeno donde hay participación del Sistema Renina-Angiotensina. Los órganos genitales masculinos son extremadamente radiosensibles y la acción de la radiación en los testículos puede afectar significativamente la espermatogénesis. En la búsqueda de potenciales radioprotectores, este estudio ha investigado fármacos antagonistas del receptor AT1 que minimizan los daños radioinduzidos en los tejidos reproductivos, por medio de la disminución del estrés oxidativo. Ratones Wistar machos fueron distribuidos en seis grupos: grupo 0 Gray (Gy) (control), grupo 5 Gy (dosis única en el área escrotal), grupo telmisartán, grupo losartán, grupo 5Gy+telmisartán y grupo 5Gy+losartán. El tratamiento empezó en el día siguiente a la irradiación con losartán 34 mg/kg (2x/día) y telmisartán 12 mg/kg (1x/día), durante 60 días. Para el análisis ultraestructural, los testículos se fijaron en glutaraldehido (2 %) y paraformaldehido (4 %) con tampón de fosfato 0,1 M, pH 7,3. El material fue post-fijado en tetróxido de osmio (1 %). Para evaluar el colágeno fue utilizado el método Picrosirius Red. Fue determinada la concentración sérica de testosterona. Los datos mostraron los efectos deletéreos de los rayos gamma sobre la ultraestructura testicular. Fue observada una rica deposición de colágeno en el intersticio en los grupos irradiados, especialmente en el irradiado y no tratado. Entre los grupos, no se detectó ninguna diferencia significativa en la concentración sérica de testosterona. Los tratamientos con telmisartán y losartán influenciaron el comienzo de la atenuación de los cambios en la ultraestructura testicular de la radiación. A pesar de que los datos sugieren que los antagonistas del receptor AT1 pueden promover radioprotección a los testículos, estudios complementarios con una duración de tratamiento más extendida son necesarios para que los efectos potencialmente positivos sean maximizados y, por supuesto, puedan mejorar la caracterizacion de la radioprotección a los parámetros reproductivos.

Effects of Continuous and Accumulated Exercise on Endothelial Function in Rat Aorta / Efeitos do Exercício Acumulado e Contínuo sobre a Função Endotelial em Aorta de Ratos

Abstract Background: The practice of exercise in short bouts repeated throughout the day may be an alternative strategy to lift people out of physical inactivity. Objective: to evaluate if accumulated exercise, as occurs in continuous exercise training, improve endothelial function in rat aorta. Methods: Wistar male rats were divided into three groups: continuous exercise (CEx, 1 hour on the treadmill) or accumulated exercise (AEx, 4 bouts of 15 minutes / day) for 5 days/week for 8 weeks, or sedentary (SED). During the training period, body weight gain and increase in exercise performance were recorded. On sacrifice day, aorta was dissected into rings (3-5 mm) and mounted on the organ bath. Results: Fitness was significantly greater in CEx and AEx rats as compared with SED animals. In addition, compared with the SED group, CEx animals had a lower body mass gain, and the aorta obtained from these animals had reduced contractile response to norepinephrine and greater acetylcholine-induced relaxation. These results were not observed in ACEx animals. Conclusions: Both CEx and AEx improved fitness, but only CEx led to reduced body weight gain and improved endothelial function.

Resumo Fundamento: A prática de exercícios em sessões curtas que se repetem ao longo do dia pode ser uma alternativa para tirar as pessoas da inatividade física. Objetivo: Verificar se o exercício acumulado, tal como ocorre com o treinamento com exercício contínuo, melhora a função endotelial na aorta de ratos. Métodos: Ratos Wistar machos foram divididos em 3 grupos: treinamento com exercício contínuo (ExC; 1 hora em esteira) ou com exercício acumulado (ExA; 4 sessões de 15 minutos ao longo do dia) por 5 dias/semana, durante 8 semanas, ou grupo sedentário (SED). Durante o treinamento, foram registrados o ganho de peso corporal e desempenho na esteira. No dia do sacrifício, anéis (3-5 mm) da aorta foram obtidos e montados em banho de órgãos. Resultados: Animais ExC e ExA mostraram aptidão física significativamente maior em comparação com os SED. Paralelamente, em comparação com SED, animais ExC tiveram menor ganho de massa corporal, e aortas retiradas desses animais mostraram respostas contrácteis à noradrenalina reduzidas e maior relaxamento induzido pela acetilcolina. Esses resultados não foram observados no grupo ExA. Conclusões: Tanto o ExC quanto o ExA melhoraram a aptidão física, mas somente o ExC foi capaz de reduzir o ganho de peso corporal dos animais e melhorar a função endotelial.

Estresse Isolado ou Associado ao Etanol Libera Prostanóides em Aorta de Ratos via ?2-Adrenoceptores / Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via ?2-Adrenoceptor

Fundamento: Estresse e etanol são ambos, independentemente, importantes fatores de risco cardiovascular. Objetivo: avaliar o risco cardiovascular do consumo de etanol e exposição ao estresse, isolados e em associação, em ratos machos adultos. Métodos: Os ratos foram separados em quatro grupos: controle, etanol (20% na água de beber durante seis semanas), estresse (imobilização 1h dia/5 dias por semana/ 6 semanas) e estresse/etanol. As curvas de concentração-resposta à noradrenalina - na ausência e na presença de ioimbina, L-NAME ou indometacina - ou fenilefrina foram determinadas em aortas torácicas com e sem endotélio. EC50 e resposta máxima (n = 8-12) foram comparadas através de ANOVA de dois fatores (two-way) / método de Bonferroni. Resultados: Estresse ou estresse em associação com o consumo de etanol aumentaram as respostas máximas de noradrenalina em aortas intactas. Essa hiper-reatividade foi eliminada pela remoção do endotélio, ou pela presença da indometacina ou ioimbina, mas não foi alterada pela presença de L-NAME. Enquanto isso, o consumo de etanol não alterou a reatividade à noradrenalina. As respostas da fenilefrina em aortas com e sem endotélio também permaneceram inalteradas independentemente do protocolo. Conclusão: O estresse crônico aumentou as respostas aórticas dos ratos à noradrenalina. Esse efeito é dependente do endotélio vascular e envolve a liberação de prostanóides vasoconstritores através da estimulação de α-2 adrenoceptores endoteliais. Além disso, o consumo crônico de etanol pareceu não influenciar as respostas de noradrenalina em aorta de rato, nem modificar o aumento de tais respostas observadas em consequência da exposição ao estresse. .

Background: Stress and ethanol are both, independently, important cardiovascular risk factors. Objective: To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Methods: Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Results: Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Conclusion: Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure. .

Effects of hyperbaric oxygen therapy as hepatic preconditioning in rats submitted to hepatic ischemia/reperfusion injury

PURPOSE: To analyze the role of hyperbaric oxygen therapy as hepatic preconditioning in rats submitted to hepatic ischemia and reperfusion. METHODS: Wistar rats were randomly divided into three groups: SHAM, rats submitted to surgical stress without hepatic ischemia and reperfusion, I/R, rats submitted to total hepatic pedicle ischemia for 30 min, followed by 5 min of reperfusion; HBOI/R, rats submitted to 60 minutes of hyperbaric oxygen therapy at 2 atm and immediately submitted to the experimental protocol of ischemia and reperfusion. Liver function was assessed by measuring serum alanine aminotransferase and aspartate aminotransferase, as well as mitochondrial function by determining states 3 and 4 of mitochondrial respiration, respiratory control rate and mitochondrial permeability transition (mitochondrial swelling). The results were analyzed by the Mann-Whitney test and all P-values <0.05 were considered significant. RESULTS: There were significant differences in serum aspartate aminotransferase values in groups SHAM vs. HBOI/R, I/R vs HBOI/R, alanine aminotranferase in groups SHAM and I/R; State 3 in SHAM groups vs. I/R, SHAM vs. HBOI/R, State 4 in I/R vs HBOI/R groups, respiratory control rate in SHAM vs I/R groups; mitochondrial swelling in SHAM vs. I/R groups, and SHAM vs HBOI/R. CONCLUSION: Hyperbaric preconditioning improved hepatic mitochondrial function and decreased serum markers of liver injury in the ischemia and reperfusion process. .

Prevençäo e controle de intoxicaçöes químicas em trabalhadores / Prevention and control of chemical intoxication in workers

Os autores mostram como e por quais meios se deve promover a proteçäo dos trabalhadores, embasados numa revisäo bibliográfica. Säo demonstrados aspectos positivos e negativos de cada modalidade de proteçäo. A monitorizaçäo biológica como meio de verificaçäo e manutençäo da saúde também referida