Peripheral artery disease and oxidative stress in patients in a program for preventing complications of diabetes mellitus and dyslipidemia / Enfermedad arterial periférica y estrés oxidativo en pacientes del programa para la prevención de complicaciones de diabetes mellitus y dislipidemias

Abstract Introduction: Peripheral artery disease (PAD) is mainly caused by atherosclerosis but also involves hyperglycemia and dyslipidemia, which trigger oxidative stress and lead to vascular damage. Objectives: To determine the prevalence of PAD in patients with type 2 diabetes mellitus (DM2) and/or prediabetes and/or dyslipidemia, to identify some risk factors and to establish whether urinary levels of 8-isoprostane-f2α (an oxidative stress marker) are elevated in patients with PAD. Design: A cross-sectional, nonprobabilistic, convenience sampling study Materials and methods: The sample included 146 patients with DM2 and/or prediabetes and/ or dyslipidemias from the Universidad Nacional de Colombia. Risk factors, symptoms related to PAD, ankle-brachial index measurement and biochemical variables (HbA1c%, fasting blood glucose, lipid profile, creatinine and albuminuria) were recorded. Urine levels of 8-isoprostane-f2α were determined by ELISA. The 8-iso-PGF2α/creatine concentration were analyzed using the statistical package R. Risk factors were compared using ANOVA/ Kruskal-Wallis. ROC curves were generated to analyze the discriminant power of the biomarkers. The joint analysis of laboratory results and risk factors was performed using multivariate logistic regressions. Results: PAD was identified in 10 diabetic patients. Risk factors were smoking, dyslipidemia, poor metabolic control, overweight or obesity. There was no evidence of increased urinary 8-isoprostane-f2α in these subjects. Conclusions: A low prevalence of PAD was found in subjects with DM2. There was no evidence of increased 8-isoprostane-f2α measured by ELISA in patients with PAD. The extension of the study with different markers of oxidative stress and the use of other techniques is recommended (Acta Med Colomb 2019; 44. DOI: https://doi.org/10.36104/amc.2019.1257).

Resumen Introducción: la enfermedad arterial periférica (EAP) es causada principalmente por aterosclerosis e intervienen la hiperglucemia y dislipidemia que desencadenan estrés oxidativo y daño vascular. Objetivo: determinar la prevalencia de EAP en pacientes con diabetes mellitus tipo 2 (DM2) y/o prediabetes y/o dislipidemias, así como algunos factores de riesgo; también, establecer si los niveles urinarios de 8-isoprostano-f2α (marcador de estrés oxidativo) están elevados en pacientes con EAP. Diseño: estudio de tipo transversal, no probabilístico, de conveniencia. Material y métodos: la muestra comprendió 146 pacientes con DM2 y/o prediabetes y/o dislipidemias de la Universidad Nacional de Colombia. Se registraron factores de riesgo, síntomas relacionados con EAP, medida índice tobillo-brazo y variables bioquímicas (HbA1c%, glucemia basal, perfil lipídico, creatinina y albuminuria). Se determinaron niveles en orina de 8-isoprostano-f2α por ELISA. Los resultados de la concentración de 8-iso-PGF2α/creatinuria se analizaron mediante el paquete estadístico R. La comparación de factores de riesgo se analizó mediante ANOVA/Kruskal-Wallis. Se generaron curvas ROC para analizar el poder discriminante del biomarcador. El análisis conjunto de resultados de laboratorios y de factores de riesgo se realizó mediante regresiones logísticas multivariantes. Resultados: se evidenció prevalencia de EAP en 10 pacientes diabéticos. Como factores de riesgo se encontraron: fumar, dislipidemia, mal control metabólico, sobrepeso u obesidad. No se evidenció aumento del 8-isoprostano-f2α urinario en estos sujetos. Conclusiones: se encontró baja prevalencia de EAP en los sujetos con DM2. No se evidenció aumento del 8-isoprostano-f2α medido por ELISA en pacientes con EAP. Se recomienda ampliar el estudio con diferentes marcadores de estrés oxidativo y uso de otras técnicas. (Acta Med Colomb 2019; 44. DOI: https://doi.org/10.36104/amc.2019.1257).

DNA damage in homocystinuria: 8-oxo-, 8-dihydro-2'-deoxyguanosine levels in cystathionine-ß-synthase deficient patients and the in vitro protective effect of N-acetyl­L­cysteine

Introduction: Homocysteine (Hcy) tissue accumulation occurs in a metabolic disease characterized biochemically by cystathionine ß-synthase (CBS) deficiency and clinically by mental retardation, vascular problems, and skeletal abnormalities. Previous studies indicate the occurrence of DNA damage secondary to hyperhomocysteinemia and it was observed that DNA damage occurs in leukocytes from CBS-deficient patients. This study aimed to investigate whether an oxidative mechanism could be involved in DNA damage previously found and investigated the in vitro effect of N-acety-L-cysteine (NAC) on DNA damage caused by high Hcy levels. Methods: We evaluated a biomarker of oxidative DNA damage in the urine of CBS­deficient patients, as well as the in vitro effect of NAC on DNA damage caused by high levels of Hcy. Moreover, a biomarker of lipid oxidative damage was also measured in urine of CBS deficient patients. Results: There was an increase in parameters of DNA (8-oxo-7,8-dihydro-2'- deoxyguanosine) and lipid (15-F2t-isoprostanes levels) oxidative damage in CBS-deficient patients when compared to controls. In addition, a significant positive correlation was found between 15-F2t-isoprostanes levels and total Hcy concentrations. Besides, an in vitro protective effect of NAC at concentrations of 1 and 5 mM was observed on DNA damage caused by Hcy 50 µM and 200 µM. Additionally, we showed a decrease in sulfhydryl content in plasma from CBS-deficient patients when compared to controls. Discussion: These results demonstrated that DNA damage occurs by an oxidative mechanism in CBS deficiency together with lipid oxidative damage, highlighting the NAC beneficial action upon DNA oxidative process, contributing with a new treatment perspective of the patients affected by classic homocystinuria.

Pesticide metabolite and oxidative stress in male farmers exposed to pesticide

BACKGROUND: The objective of this study was to measure malondialdehyde (MDA) and isoprostane which has been used as an index of lipid injury, 8-hydroxy-2′-deoxyguanosine (8-OHdG), which has been used as an index of DNA damage, and dialkyl-phosphate (DAP), which has been used to quantify pesticide exposure, and to investigate the relationship between pesticide exposure and oxidative stress. METHODS: This study was a cross-sectional study that evaluated 84 male farmers exposure to pesticide. In this study, 8-OHdG, isoprostane, and MDA were measured as oxidative stress indices, and dialkyl-phosphate (dimethylphosphate(DMP), diethylphosphate(DEP), dimethylthiophosphate(DMTP), and diethylthiophosphate (DETP)) excreted in the urine was also measured to evaluate pesticide exposure. A linear regression analysis was performed to investigate the relationship between pesticide metabolites, and oxidative stress biomarkers. RESULTS: A Correlation analysis was performed for pesticide exposure month (PEI), cumulative exposure index (CEI), and DAP as well as the concentration of the oxidative stress biomarkers. The PEM significantly and positively correlated to the levels of 8-OHdG, isoprostane, CEI, and DMP. CEI showed a correlation to 8-OHdG and PEM. DMP, DEP, and DETP showed a positive correlation to 8-OHdG, isoprostane, and MDA. A correlation analysis was adjusted some demographic characteristics, such as age, smoking, drinking, and exercise to determine the relationship between pesticide exposure and oxidative stress. The 8-OHdG, isoprostane, and MDA levels were significantly related to the DMP (ß = 0.320), DEP (ß = 0.390), and DETP (ß = 0.082); DMP (ß = 0.396), DEP (ß = 0.508), and DETP (ß = 0.504); and DMP (ß = 0.432), DEP (ß = 0.508), and DETP (ß = 0.329) levels, respectively. CONCLUSIONS: The concentration between oxidative stress biomarkers and the pesticide metabolite were a positive correlation. Indicators of oxidative stress was associated with a pesticide metabolite DMP, DEP, and DETP. Therefore, Pesticide exposure and oxidative stress were relevant.

Lead Exposure and Oxidative Stress in Coal Miners / 生物医学与环境科学（英文）

We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups: three groups according to the number of consecutive working days, and a fourth control group. Miners who worked for three consecutive days had higher blood levels of lead and 8-isoprostane than the control group (P < 0.001). Correlation between lead and 8-isoprostane was of medium strength (r = 0.512, P < 0.001). Short-term lead environmental exposure can potentially harmful and should be considered when formulating improvements in working processes.

Eicosanoid Mediators in the Airway Inflammation of Asthmatic Patients: What is New?

Lipid mediators contribute to inflammation providing both pro-inflammatory signals and terminating the inflammatory process by activation of macrophages. Among the most significant biologically lipid mediators, these are produced by free-radical or enzymatic oxygenation of arachidonic acid named "eicosanoids". There were some novel eicosanoids identified within the last decade, and many of them are measurable in clinical samples by affordable chromatography-mass spectrometry equipment or sensitive immunoassays. In this review, we present some recent advances in understanding of the signaling by eicosanoid mediators during asthmatic airway inflammation. Eicosanoid profiling in the exhaled breath condensate, induced sputum, or their metabolites measurements in urine is complementary to the cellular phenotyping of asthmatic inflammation. Special attention is paid to aspirin-exacerbated respiratory disease, a phenotype of asthma manifested by the most profound changes in the profile of eicosanoids produced. A hallmark of this type of asthma with hypersensitivity to non-steroid anti-inflammatory drugs (NSAIDs) is to increase biosynthesis of cysteinyl leukotrienes on the systemic level. It depends on transcellular biosynthesis of leukotriene C₄ by platelets that adhere to granulocytes releasing leukotriene A₄. However, other abnormalities are also reported in this type of asthma as a resistance to anti-inflammatory activity of prostaglandin E₂ or a robust eosinophil interferon-γ response resulting in cysteinyl leukotrienes production. A novel mechanism is also discussed in which an isoprostane structurally related to prostaglandin E₂ is released into exhaled breath condensate during a provoked asthmatic attack. However, it is concluded that any single eicosanoid or even their complex profile can hardly provide a thorough explanation for the mechanism of asthmatic inflammation.

Daño a células endoteliales en cultivo inducido por el isoprostano 8-iso-PGF2a / Damage to cultured endothelial cells induced by isoprostane 8-iso PGF2

INTRODUCCIÓN: el endotelio vascular posee un papel esencial en los procesos asociados a la enfermedad cardiovascular. Existe estrecha relación entre el desbalance redox de estas células y la aparición y evolución de estas enfermedades. Entre los marcadores de daño oxidativo a los lípidos de membranas se encuentra el isoprostano 8-iso-PGF2a, que aumenta en estos pacientes. OBJETIVO: evaluar el efecto del isoprostano 8-iso-PGF2a sobre células endoteliales en cultivo y la protección con la proteína de estrés térmico a-cristalina. MÉTODOS: se cultivaron células endoteliales de la línea H5V y se evaluó el efecto del isoprostano 8-iso-PGF2a y del análogo del tromboxano A2, U46619, sobre la supervivencia celular. Se evaluó el efecto protector de la proteína de estrés térmico a-cristalina a través de la incubación de los cultivos con 1 mg/ml de la proteína previo a la inducción del daño con los compuestos en estudio. RESULTADOS: la supervivencia celular disminuyó proporcional al aumento de la concentración del isoprostano y del U46619. La a-cristalina aumentó la supervivencia celular en un 20 % al preincubar los cultivos sometidos al efecto de ambos compuestos. CONCLUSIONES: el isoprostano 8-iso-PGF2a, además, de ser un marcador de daño oxidativo puede ser considerado un inductor directo de daño a las células del endotelio vascular, efecto mediado a través, de la generación de tromboxano A2 o la activación de su receptor. La proteína de estrés térmico a-cristalina, añadida de forma exógena, puede considerarse un protector endotelial.

INTRODUCTION: the vascular endothelium plays an essential role in processes associated with cardiovascular disease. There is a close relationship between redox imbalance in these cells and the appearance and evolution of such diseases. Increased isoprostane 8-iso PGF2 is among the markers of oxidative damage to membrane lipids in these patients. OBJECTIVE: evaluate the effect of isoprostane 8-iso PGF2 on cultured endothelial cells and the protection provided by -crystallin heat-shock stress protein. METHODS: endothelial cells from line H5V were cultured to evaluate the effect of isoprostane 8-iso PGF2 and thromboxane A2 analog U46619 on cell survival. An evaluation was conducted of the protective effect of -crystallin heat-shock stress protein by incubation of the cultures with 1 mg/ml of the protein prior to damage induction with the study compounds. RESULTS: cell survival decreased as isoprostane and U46619 concentration increased. -Crystallin increased cell survival by 20% upon preincubation of the cultures subjected to both compounds. CONCLUSIONS: besides being an oxidative damage marker, isoprostane 8-iso PGF2 may be considered a direct inducer of damage to vascular endothelial cells. This effect is mediated by the generation of thromboxane A2 or the activation of its receptor. Added exogenously, -crystallin heat-shock stress protein may be considered to be an endothelial protector.

Avaliação do status de magnésio e da sua associação com o estresse oxidativo e as citocinas inflamatórias na pré-eclâmpsia / Assessment of the magnesium status and its association with oxidative stress and inflammatory cytokines in preeclampsia

O objetivo deste trabalho foi avaliar o status de magnésio (Mg) e a sua relação com o estresse oxidativo e as citocinas inflamatórias na pré-eclâmpsia (PE). Participaram do estudo, 18 gestantes saudáveis (controle - CT) e 18 gestantes com PE, diagnosticadas com pressão arterial >= 140/90 mmHg, proteinúria >= 0,3 g/24 h e sem doenças associadas. Sangue e urina de 24 horas foram coletados para análise de status de Mg, estresse oxidativo [malondialdeído (MDA), 8-isoprostano urinário e a atividade antioxidante das enzimas catalase (CAT) e glutationa peroxidase (GSH-Px)], a concentração de óxido nítrico (NO), e das citocinas inflamatórias [proteína C reativa, interleucina 6 (IL-6) e fator de necrose tumoral (TNF-α)]; Foi aplicado um questionário quantitativo de frequência alimentar para gestantes. As comparações entre os grupos foram feitas pelos testes Qui-quadrado, t-Student ou Mann Whitney. O coeficiente de correlação de Spearman foi usado para verificar associação entre as variáveis. A análise do Receiver Operating Characteristic (ROC) foi realizada para identificar as variáveis que melhor discriminassem os grupos (α=5%). As concentrações de Mg plasmático e eritrocitário, bem como a concentração de NO, a atividade da CAT e as concentrações de TNF-α e IL-6 foram maiores na PE do que no CT. Associações positivas entre o Mg plasmático e a proteinúria (p=0,04), o TNFα (p=0,03) e a IL-6 (p=0,02) foram verificadas; associações negativas foram encontradas entre a atividade da CAT e a concentração de 8-isoprostano urinário (p=0,02) e entre a atividade da GSH-Px e os níveis de pressão arterial diastólica (p=0,01). A análise ROC mostrou que o Mg plasmático e o TNF-α foram as variáveis que mellhor discriminaram as gestantes com PE das CT. Os resultados mostraram que o estresse oxidativo não foi evidente na fisiopatologia da PE, possivelmente devido aos mecanismos antioxidantes compensatórios do organismo. A inflamação e os eventos inerentes à PE, como vasoconstrição, podem ter promovido as alterações no status de Mg

The aim of this study was to assess the magnesium (Mg) status and its relationship with oxidative stress and inflammatory cytokines in preeclampsia (PE). Were included 18 healthy pregnant women (CT- control) and 18 PE, diagnosed with blood pressure >= 140/90 mmHg, proteinuria >= 0,3 g/24 h, and without other diseases. Blood and 24h urine were collected for analyses of the Mg status, oxidative stress [malondialdehyde (MDA), 8-isoprostane urinary and activities of the antioxidant enzymes: catalase (CAT) and glutathione peroxidase (GSH-Px)], nitric oxide (NO) and inflammatory cytokines concentrations [protein C reactive, interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α); Furthermore, a quantitative food frequency questionnaire was applied to pregnant women. The comparisons between groups were done by Chi-square, t-Student or Mann Whitney tests. Spearman correlation coefficient was used to verify association among variables and the Receiver Operating Characteristic (ROC) analysis was performed to identify variables that better discriminated the groups (α = 5 %). The Mg concentration, in plasma and in erythrocyte, as well as NO concentration, CAT activity and TNF-α and IL-6 concentrations were higher in PE than CT group. Positive associations between plasma Mg and proteinuria (p=0,04), TNF-α (p=0,03) and IL-6 (p=0,02) were verified; Negative associations were found between CAT activity and 8-isoprostane urinary concentration (p=0,02) and between GSH-Px activity and diastolic blood pressure levels (p=0,01). ROC analyses showed that plasma Mg and TNF-α were the variables which better discriminate pregnant women with PE from CT. The results showed that oxidative stress was not evident in physiopathology of PE, possibly due to compensatory antioxidant mechanisms present in the body. The inflammatory and the events inherent to PE, such as vasoconstriction, possibly have promoted changes in Mg status

NADPH oxidasa: rol en aterosclerosis y función plaquetaria / NADPH OXIDASE: role in atherosclerosis and platelet function

Reactive oxygen species have emerged as important molecules in cardiovascular function. Recent research has shown that the NADPH oxidases are important sources of superoxide in vascular cells and myocytes. The NADPH oxidases vascular share some, but not all, of the characteristics of the enzyme in neutrophils, both produce superoxide, which is metabolized to hydrogen peroxide, at the same time these reactive oxygen species serve as second messengers activate multiple intracellular signalling pathways. NADPH oxidases are essential in the physiological response of vascular cellsto pathological states such as atherosclerosis, and are functionally relevant in activation and recruitment of platelets. Recent studies suggest a key role for NADPH oxidase in the formation of a specific product from the oxidation of arachidonic acid, and a potential role in the process of recruitment of platelets. Taking into account these characteristics and evidence of the involvement of the NADPH oxidases in cardiovascular diseases as the thrombosis, inhibition of this enzymatic system appears as a promising therapy to treat and prevent these diseases.

Mayor actividad de rho kinasa en leucocitos circulantes se asocia a estrés oxidativo y rigidez arterial en hipertensos diabéticos / Increased Rho-kinase activity in peripheral leukocytes is associated to oxidative stress and decreased compliance of the arterial wall in diabetic hypertensive patients

Introducción: La vía intracellular de RhoA/Rho kinasa es activada por agonistas de receptores acoplados a proteínas G pequeñas unidas a membrana. Su activación está relacionada al remodelado cardiovascular patológico. Previamente hemos observado aumento de actividad de Rho kinasa (ROCK) en pacientes con hipertensión arterial (HT) e hipertrofia ventricular izquierda como daño de órgano blanco. Pero su activación en relación a la diabetes no ha sido explorada en estos pacientes. Objetivo: Evaluar activación de Rho kinasa y parámetros de estrés oxidativo en pacientes hipertensos con diabetes tipo II (DMII). Métodos: Estudio comparativo entre pacientes con HT sin tratamiento, HT con DMII y hemoglobina glicosi-lada Alc > 7,5 por ciento y un grupo control normotenso. Se realizó ecocardiograma de superficie. Se midió activación de ROCK en leucocitos circulantes midiendo MYPT1 fosforilado/total (p/t) por Western blot y la velocidad de pulso carotídeo-femoral (PWV) para estimar distensibilidad arterial. El stress oxidativo se estimó midiendo ma-londialdehído (MDA) y 8-isoprostano (8-ISO) en suero. Resultados: Se incluyeron 21 pacientes hipertensos con DMII, 38 pacientes hipertensos sin DMII y 34 controles normotensos. La edad promedio fue 51 +/- 0,9; 48 +/- 0,9 y 52 (p: NS) +/- 1,1 y el 47 por ciento, 50 por ciento y 52 por ciento (p: NS) eran mujeres respectivamente. Los pacientes HT con DMII presentaron MYPTl p/t (5,6 +/- 1,3; 3,6 +/- 0,4; 2,1 +/- 0,1 p< 0,01), MDA (1,8 +/- 0,4/

Background: Rho/Rho-kinase intracellular pathway is activated by membrane bound small G-proteins. Activation of Rho/Rho-kinase pathway is related to pathologic cardiac remodeling. We have previously observed this activation (ROCK) in hypertensive patients with left ventricular hypertrophy. The influence of diabetes in this relationship has not been explored. Aim: to evaluate the activation of Rho-kinase and oxi-dative stress in hypertensive patients with type II diabetes (DMII). Methods: A comparative study between patients with untreated hypertension (HT), hypertensive patients with diabetes and hemoglobin A1c > 7.5 percent and normotensi-ve control subjects was performed. LVH was assessed by echocardiography. ROCK activity was measured in peripheral leukocytes by Western blot determination of phosphorilated / total MYPT1 ratio. Arterial compliance was determined by the relationship of carotid and femoral velocity signals (PWV) Oxidative stress was estimated by serum levels of malondialdehyde (MDA) and 8-isoprostane (8-ISO). Results: Hypertensives with DMII (n=21) had a mean age of 51 +/- 0.9 years, and 47 percent were females. Corresponding figures for 38 hypertensive patients without DM and 34 control patients were 48 ± 0,9 and 52 +/- 1,1 (NS) and 50 percent and 52 percent females, respectively (NS). The MYPT1 p/t ratio was 5,6 +/- 1,3; 3,6 +/- 0,4; 2,1 +/- 0,1 (p<0.01) in the 3 groups, respectively. MDA for the 3 groups was 1,8 +/- 0,4/

Efecto del ibuprofeno y ácido acetilsalicílico sobre el deterioro cognitivo, poder antioxidante total e isoprostanos en suero / The effect of ibuprofen and acetylsalicylic acid on cognitive impairment, total antioxidant power and isoprostane serum

Introducción: Existen estudios controvertidos sobre la prevención de la enfermedad de Alzheimer y el uso de antiinflamatorios no esteroideos. El objetivo fue evaluar el efecto del ibuprofeno y ácido acetilsalicílico sobre el deterioro cognitivo, poder antioxidante total (PAT) e isoprostanos (8-iso-PGF2á) séricos. Material y métodos: Entre abril de 2004 y febrero de 2006, a 18 mujeres mayores de 55 años de edad se les realizó escrutinio con la Prueba Mínima del Estado Mental de Folstein (MMSE); Prueba Corta para la Evaluación de la Memoria y la Atención, Syndrome Kurtz Test (SKT) y Escala de Depresión Geriátrica de Yasevage. Fueron asignadas aleatoriamente para recibir 400 mg/día de ibuprofeno (n=9) o 500 mg/día de ácido acetilsalicílico (n=9) durante un año. En la visita basal, seis meses y al año se determinó PAT y 8-iso-PGF2á séricos. Resultados: A un año de intervención, en cinco mujeres (55.6%) el MMSE aumentó cuatro puntos con ácido acetilsalicílico comparado con tres (33.3%) de ibuprofeno (p=0.028). El PAT aumentó (p=0.01) y disminuyeron los 8-iso-PGF2á (p=0.01) en ambos grupos en comparación con los valores basales. Conclusiones: Ambos medicamentos mejoraron el estado cognitivo y el perfil oxidativo en la población estudiada.

INTRODUCTION: There are controversial studies on the prevention of Alzheimer's disease with nonsteroidal antiinflammatory drugs (NSAIDs). The objective of this study was to evaluate the effect of ibuprofen and acetylsalicylic acid on cognitive impairment, serum total antioxidant power (TAP) and isoprostane (8-iso-PGF2alpha). METHODS: From April 2004 to February 2006, a Folstein mini-mental state (MMSE), Syndrome Kurtz Test (SKT) and a geriatric depression scale (Yasevage) were applied to eighteen, 55-56 years old eligible women. All women (n= 18) with normal cognitive state were randomized to ibuprofen 400 mg per day (n= 9) and acetylsalicylic acid 500 mg per day (n= 9) for one year. Serum TAP and 8-iso-PGF2alpha were performed at baseline, after six months and one year of treatment. RESULTS: After one year of treatment with acetylsalicylic acid five women (55.6%) raised their score 4 points in MMSE compared with 3 points increased (33.3%) showed by the ibuprofen group. TAP increased (p=0.01) and 8-iso-PGF2alpha reduced (p=0.01) in both groups compared with baseline. CONCLUSIONS: Both drugs improved the cognitive state andoxidative status of our population.

Exposição aguda ao material particulado total em suspensão proveniente de diferentes fontes e suas repercussões nas respostas inflamatórias, sistêmica e local, em ratos / Acute exposure to total suspended particles from different sources and their impacts on both, systemic and local inflammatory responses, in rats

A poluição do ar está associada ao aumento da morbimortalidade pulmonar e cardiovascular. O objetivo desse estudo foi o de avaliar e comparar a resposta inflamatória à exposição a três diferentes tipos de particulado total em suspensão (fonte automativa, industrial e da queimada da cana de açúcar), às baixas concentrações e de forma aguda; comparando-as ao grupo controle (black carbon). Os resultados mostraram uma maior inflamação pulmonar induzida pela fonte automotiva, uma maior oxidação cardíaca induzida pela biomassa de queima de cana de açúcar, e uma mais intensa alteração na contagem de células sanguíneas nas partículas industriais. Concluímos que o aerossol ambiente pode induzir inflamação subclínica a baixas concentrações, e que a composição do particulado afetou a magnitude e o tipo de resposta.

Air pollution is associated with increased pulmonary and cardiovascular morbidity and mortality. The objective of this study is to assess and to compare inflammatory responses of acute exposures to total suspended particles generated from three different sources (automotive, burning cane sugar and industrial) at lower concentrations, comparing to the control group (carbon black). The results showed a great pulmonary inflammation induced by automotive source, a strong cardiac oxidation induced by sugar cane burning source, and an intense alteration in the blood cells count induced by the industrial source. We concluded that the environmental aerosol can induce sub clinic inflammation at lower concentrations and that the composition of total suspended particles affects magnitude and kind of responses.

Urinary 8-isoprostane and S100B protein concentrations as predictors of hypoxic-ischemic brain damage in asphyxiated neonates

Newborn infants with perinatal asphyxia are prone to the development of hypoxic-ischemic encephalopathy [HIE]. To date, there are no reliable methods for proper identification of infants who are at high risk of HIE after asphyxial insult. We sought to evaluate urinary levels of a lipid peroxidation marker, 8-isoprostane, and a brain specific protein, S100B protein, as non-invasive tools that might help early identification of postasphyxial hypoxic-ischemic brain damage and prediction of its outcome. Thirty term neonates with perinatal asphyxia were evaluated in comparison to 15 matched healthy controls. Urinary concentrations of 8-isoprostane [by ELISA] and S100B protein [by immunoluminometric technique] were determined at first urination [time 1] and repeated in a second sample obtained 24-48 hours postnatally [time 2]. Asphyxiated neonates were clinically monitored for their neurological pattern over the first two postnatal weeks and were subsequently classified as mild [grade I, n=8], moderate [grade II, n=12] and severe [grade III, n=10] HIE. Eleven of these neonates [36.7%] died in the NICU. The results obtained were interpreted in relation to the grade of HIE severity and mortality. Urinary concentrations of 8-isoprostane and S100B protein were significantly higher in asphyxiated neonates at both monitored times, as compared to controls. Levels of both markers were related to the grade of HIE severity being significantly higher in neonates who developed grade II as compared to grade I, while highest levels were found in grade III. A significant increase in urinary 8-isoprostane from time 1 to time 2 was only found in grade III [p<0.05] while S100B protein increased over that time period in grades II and III [p<0.01, respectively]. Survivors showed significantly lower mean level of each marker as compared to those with fatal outcome [p<0.001, respectively], at both monitored times. Diagnostic performance tests revealed that S100B protein was superior to 8-isoprostane, at the two monitored times, for prediction of HIE severity and mortality. At first urination, a cut-off value for S100B protein of 0.3 micro g/L could best predict development of grades II and III HIE with a positive predictive value [PPV] of 100% and an efficacy of 95.5%. Meanwhile, an optimum cut-off value of 6.89 microg/mg creatinine for 8-isoprostane, had a PPV of 90.48% and an efficacy of 88.89% for grades II and III prediction. As predictors of mortality at first urination, an optimum cut-off value for S100B protein of 2.12 micro g/L and for 8-isoprostane of 10.4 micro g/mg creatinine had corresponding PPVs of 90.9% and 90%, respectively and efficacies of 93.3% and 90%, respectively. There was no significant difference in the overall diagnostic performance of each of the two markers either for disease severity or mortality prediction between both monitored times [p>0.05, respectively]. 8-isoprostane and S100B protein levels are increased in urine following birth asphyxia. S100B protein is superior to 8-isoprostane for prediction of both HIE severity and mortality. It could be speculated that measurement of urinary concentrations of these markers, soon after birth, could serve as a clinically useful and relatively simple non-invasive tool to predict the risk for developing HIE following birth asphyxia and its short-term outcome

8-Isoprostane and endothelin-1 as markers of oxidative stress in smokers

The aim of this study was to quantify oxidative stress in 40 smokers with chronic obstructive pulmonary disease [COPD], 25 healthy smokers and 20 healthy nonsmokers, as reflected by 8-isoprostane [8-IP] as a marker of lipid peroxidation, protein carbonyl as an index of protein oxidation and endothelin-1 [ET-1] concentrations. This study was also undertaken to determine whether plasma 8-IP, protein carbonyl and ET- 1 status correlated with lung function as assessed by forced expiratory volume in one second [FEV1] and forced vital capacity [FVC] in smokers and in smokers with COPD. Plasma levels of 8-IP and ET-1 were measured by ELISA technique and protein carbonyl was determined by colorimetric method. Antioxidant status, assessed by measuring the glutathione [GSH] and vitamin C levels. Plasma 8-IP, ET-1 and protein oxidation levels were significantly increased in smokers with COPD [45.2 +/- 3.2 pg/ml, 159.6 +/- 9.8 pg/mg protein and 0.55 +/- 0.09 nmol/mg protein respectively] and in healthy smokers [30.6 +/- 2.1 pg/ml, 142 +/- 7.7 pg/mg protein and 0.37 +/- 0.04, nmol/mg protein, respectively] compared with healthy nonsmokers [13.2 +/- 0.92 pg/ml, 72.5 +/- 5.2 pg/mg protein and 0.22 +/- 0.01 nmol/mg protein respectively]. The mean differences of plasma antioxidants, GSH [24.3 +/- 1.61, 28.1 +/- 2.2 and 36.3 +/- 1.93 nmol/mg protein] and vitamin C [1.92 +/- 0.03, 3.17 +/- 0.1 and 5.26 +/- 0.17 mg/L] were significantly decreased in smokers with COPD and healthy smokers compared with healthy nonsmokers, respectively. Significant negative correlations were found between Spirometric data measured as FEV 1% predicted and the plasma levels of 8-IP, ET- 1 and protein oxidation in smokers with COPD, healthy smokers, or healthy nonsmokers. On the other hand, there were significant positive correlations between FEV1% predicted and the levels of plasma vitamin C and GSH in the three studied groups. Conclusions: These data confirm decreased antioxidant capacity [GSH and vitamin C] and increased oxidative stress markers [8-IP, ET- I and protein oxidation] in healthy smokers and smokers with COPD, indicating the presence of systemic oxidative stress. However, relationship was found between plasma oxidant/antioxidant levels and measurements of airflow limitation in either healthy smokers or in smokers with COPD

Umbilical Cord Arterial Concentrations of Isoprostane(8-iso-PGF2alpha) in Newborn Infants

PURPOSE: We measured the umbilical cord arterial concentrations of isoprostane(8-iso-PGF2alpha) and intended to decide whether the umbilical cord arterial concentrations of isoprostane could be used as a useful parameter for lipid peroxidation in newborn infants. METHODS: The isoprostane and malondialdehyde(MDA) concentrations of the umbilical cord were measured by enzyme immunoassay and TBARS(thiobarbituric acid reactive substance) assay in 33 preterm and 28 term infants, respectively. The concentrations of isoprostane and MDA were compared between preterm infants and term infants, and were analysed for association with perinatal risk factors and neonatal complications. RESULTS: Umbilical cord arterial concentrations of isoprostane were 704.7+/-635.6 pg/mL and 421.9+/-306.5 pg/mL in preterm and term infants, respectively. Umbilical cord arterial concentrations of MDA were 44.0+/-22.9 micrometer/L and 26.2+/-10.7 micrometer/L in preterm and term infants, respectively. Umbilical cord arterial concentrations of isoprostane and MDA in preterm infants were significantly higher than those in term infants(P<0.05). The umbilical cord arterial concentrations of isoprostane were significantly associated with perinatal risk factors such as fetal distress, oligohydramnios, and breech delivery in preterm infants and pregnancy-induced hypertension in term infants(P<0.05). CONCLUSION: Umbilical cord arterial concentrations of isoprostane in preterm infants were higher than those in term infants, and those are significantly associated with some perinatal risk factors.

Changes in the Levels of Eicosanoids and Isoprostane (8-iso-PGF2alpha) in the Newborn Rat Brain after Hypoxic-Ischemic Injury

PURPOSE: The changes in the levels of eicosanoids and isoprostane (8-iso-PGF2alpha) were investigated in brain tissue of 7 day-old rats after hypoxic-ischemic (HI) injury. METHODS: The 7 day-old newborn rats underwent right unilateral common carotid artery ligation followed by exposure to hypoxia with 8% oxygen for 150 minutes. There after, the pups were decapitated during reoxygenation 21% period of 0, 1, 6, 24, and 72 hours and their cerebral hemisheres were dissected through sagittal plane. Ipsilateral and contralateral cerebral hemesheres to common carotid artery ligation were used to determine the water content for estimation of severity of brain edema (n=5) and to measure the levels of eicosanoid and isoprostane (n=7). The levels of 6-keto-PGF1alpha, TXB2, and PGE2 were measured by RP-HPLC (reversed-phase high-performance liquid chromatography) and the levels of isoprostane (8-iso-PGF2alpha) were measured by enzyme immunoassay. The changes of eicosanoid and isoprostane levels during reoxygenation period were observed and comparisons between ipsilateral and contralateral hemispheres were done. RESULTS: The edema of ipsilateral cerebral hemesheres to common carotid artery ligation was more severe than that of contralateral cerebral hemisheres (P<0.05). The levels of 6-keto-PGF1alpha, TXB2, and PGE2 were found to increase during the early period of reoxygenation after HI insult, peak at 1 hour, and then decrease to the control levels at 72 hour (P<0.05). But, the levels of 8-iso-PGF2alpha did not significantly increase during the period of reoxygenation. The levels of 6-keto-PGF1alpha, TXB2, and PGE2 of ipsilateral hemispheres had a tendency to be higher than those of contralateral hemispheres during the initial 6 hour reoxygenation period, but the levels of 8-iso-PGF2alpha of ipsilateral hemispheres were significantly higher than those of contralateral hemispheres during the relatively later reoxygenation period (P<0.05). CONCLUSION: Reoxygenation after hypoxic-ischemic injury increased the levels of 6-keto-PGF1alpha, TXB2, and PGE2 in 7 day-old rat brain during the early period of reoxygenation, but the levels of isoprostane (8-iso-PGF2alpha) were not significantly increased during the reoxygenation period after HI injury.

Simultaneous HPLC analysis of arachidonic acid metabolites in biological samples with simple solid phase extraction

A reversed-phase high-performance liquid chromatography (RP-HPLC) has been developed to analyze the metabolites of arachidonic acid based on the specificities of ultraviolet absorption of these various metabolites and is sensitive to the nanogram level. This procedure makes it possible to extract complex mixtures of eicosanoids efficiently with a single step and to analyze them simultaneously by RP-HPLC from biological samples using octadesylsilyl silica extraction column and PGB2 as an internal standard. The cyclooxygenase, products (prostaglandin (PG)D2, PGE1, PGE2, PGF1alpha, PGF2alpha, 6-keto-PGF1alpha, and thromboxane B2 (TXB2)) and lipid peroxidation product, isoprostanes, of arachidonic acid were monitored by one isocratic HPLC system at 195 nm wavelength. The lipoxygenase products (leukotriene(LT)B4, LTC4, LTD4, and 5-hydroxyeicosatetraenoic acid (5-HETE), 12-HETE, 15-HETE) were measured by another isocratic HPLC system at 280 nm for LTs and 235 nm for HETEs. This method provides a simple and reliable way to extract and assess quantitatively the final arachidonic acid metabolites.