Resumo Introdução: A perfusão coclear prejudicada é um fator etiológico importante na perda auditiva neurossensorial súbita idiopática (PANSSI). O estresse oxidativo mostrou ser um fator de risco para danos oxidativos. Objetivos: Investigamos o papel do estresse oxidativo na PANSSI mediante a comparação dos níveis séricos de moléculas oxidantes e antioxidantes, inclusive homeostase de tiol/dissulfeto, paraoxonase, paraoxonase estimulada, arilesterase, ceruloplasmina e mieloperoxidase em pacientes com e sem recuperação após o tratamento. Método: A quantidade de dissulfeto dinâmico foi calculada mediante a determinação de metade da diferença entre os tiois totais e os tiois nativos. Após a determinação das quantidades de tiol nativo, tiol total e dissulfeto, as razões percentuais de dissulfeto/tiol total, tiol nativo/tioltotal e dissulfeto/tiol nativo foram calculadas e depois comparadas entre os dois grupos. Além disso, a relação clínica entre a recuperação audiológica e os níveis de tiol nativo, tiol nativo/tiol total, dissulfeto, dissulfeto/tiol nativo e dissulfeto/tiol total foi investigada. Amostras de sangue também foram analisadas para avaliar os níveis de paraoxonase, paraoxonase estimulada, arilesterase, ceruloplasmina e mieloperoxidase. Resultados: Uma diferença significante foi encontrada entre os dois grupos em relação ao estado oxidante total e aos níveis de dissulfeto, dissulfeto/tiol nativo, dissulfeto/tiol total, tiol nativo/tiol total (p = 0,001, p = 0,001, p = 0,001, p = 0,003, p = 0,001, p = 0,002, respectivamente). Porém, não foi encontrada diferença significante entre os dois grupos em relação aos níveis de paraoxonase, paraoxonase estimulada, ceruloplasmina e mieloperoxidade (p> 0,05 para todos). Conclusão: Os resultados apoiaram a hipótese comum de que as doenças vasculares são a principal causa de PANSSI e que, em última análise, outros fatores etiológicos resultam em doenças vasculares. Os equilíbrios de oxidante-antioxidante e tiol-dissulfeto estavam prejudicados no grupo PANSSI.

Abstract Introduction: Impaired cochlear perfusion is a major etiological factor in idiopathic sudden sensorineural hearing loss. Oxidative stress has been shown to be a risk factor for oxidative damage. Objectives: We investigated the role of oxidative stress in idiopathic sudden sensorineural hearing loss by comparing serum levels of oxidant and antioxidant molecules including thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin and myeloperoxidase in patients who did and did not recover after treatment. Methods: The amount of dynamic disulfide was calculated by determining half of the difference between the total thiols and native thiols. After the determination of native, total thiol, and disulfide amounts, the disulfide/total thiol percent ratio, native thiol/total thiol ratio and disulfide/native thiol percent ratio were calculated and then compared between the two groups. Additionally, clinical relationship between audiological recovery and native thiol, disulfide, disulfide/native thiol percent ratio, and disulfide/total thiol percent ratio levels was investigated. Blood samples were also analyzed for the assessment of thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin, and myeloperoxidase levels. Results: A significant difference was found between the two groups with regard to total oxidant status disulfide, disulfide/native thiol percent ratio, disulfide/total thiol percent ratio, and native thiol/total thiol ratio levels (p = 0.001, p = 0.001, p = 0.001, p = 0.003, p = 0.001, p = 0.002, respectively). However, no significant difference was found between the two groups with regard to thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, ceruloplasmin, and myeloperoxidase levels (p > 0.05 for all). Conclusion: The results supported the common hypothesis that vascular pathologies are the primary cause of idiopathic sudden sensorineural hearing loss and that other etiological factors ultimately result in vascular pathologies. The oxidant-antioxidant and thiol-disulfide balances were impaired in the idiopathic sudden sensorineural hearing loss group.

Resumo Fundamento A espessura médio-intimal (EMI) da artéria aorta abdominal (EMI-A) pode ser um marcador precoce de aterosclerose subclínica e um indicador objetivo de estresse oxidativo em pacientes com talassemia menor. Objetivo Avaliar se as EMIs da artéria aorta e da artéria carótida (EMI-C) se alteram com estresse oxidativo, e examinar a relação entre esses parâmetros em pacientes com talassemia menor. Métodos O estudo incluiu 80 pacientes diagnosticados com talassemia menor, e 50 indivíduos sadios com idade e sexo similares. Após procedimentos de rotina, as amostras de sangue foram coletadas dos grupos de estudo para a medida da homeostase tiol/dissulfeto e da albumina modificada pela isquemia (AMI). As medidas da EMI-C foram realizadas a partir de quatro regiões diferentes (artéria carótida externa direita e esquerda e artéria carótida interna direita e esquerda) por ultrassonografia, e a medida da EMI-A foi realizada por ultrassonografia abdominal. Um valor de p<0,05 foi definido como estatisticamente significativo. Resultados Nos pacientes com talassemia menor, os níveis de tiol nativo e tiol total, e a razão tiol nativo/tiol total foram mais baixos, e os valores de AMI, razão dissulfeto/tiol nativo, e razão dissulfeto/tiol total foram mais altos que no grupo controle. A EMI-A foi significativamente maior no grupo de pacientes com talassemia menor que nos controles (1,46±0,37 vs 1,23±0,22 e p<0,001). Quando os parâmetros associados com EMI-A na análise univariada foram avaliados por regressão linear multivariada, EMI-A apresentou uma relação positiva, e os níveis de tiol nativo e tiol total apresentaram uma forte relação negativa com AMI (p<0,01). Conclusão Nós demonstramos, pela primeira vez, um aumento no estresse oxidativo com a elevação da EMI-A, e valores inalterados da EMI-C em pacientes com talassemia menor.

Abstract Background Abdominal aortic intima media thickness (A-IMT) may be an early marker of subclinical atherosclerosis and an objective indicator of increased oxidative stress in beta-thalassemia minor patients. Objective To evaluate whether aortic and carotid IMTs change with oxidative stress and to assess the relationship between these parameters in beta-thalassemia minor patients. Methods The study included 80 patients diagnosed with beta-thalassemia minor, and 50 healthy individuals with similar age and gender. After routine procedures, blood samples were collected from the study groups for thiol-disulfide hemostasis and ischemia-modified albumin (IMA). C-IMT measurements were performed in four different regions (right and left internal and external carotid artery) by ultrasonography. In addition, A-IMT measurement was performed by abdominal ultrasonography. Statistically significant p value was set as <0.05 for all comparisons. Results In beta-thalassemia minor patients, native thiol, total thiol and native thiol / total thiol ratio were lower, and the IMA, disulfide / native thiol ratio and disulfide / total thiol ratios were higher than in healthy control group. A-IMT measurement was significantly higher in beta-thalassemia minor group than controls (1.46±0.37 vs 1.23±0.22 and p<0.001). When the parameters associated with A-IMT in univariate analysis were evaluated by multivariate linear regression analysis, A-IMT was positively related, and native thiol and total thiol levels were negatively and closely related to IMA (p<0.01). Conclusion We demonstrated, for the first time, that oxidative stress status increased with increased A-IMT, while C-IMT remained unchanged in beta-thalassemia minor patients.

ABSTRACT Objective: Graves’ ophthalmopathy (GO) is a vision-threatening finding observed in approximately half of Graves’ disease patients. The pathophysiology of GO is unclear, and one of the suspected factors is oxidative stress. In our study, we compared the relationship between proptosis and SH-SS in patients diagnosed with GO. Materials and methods: In this prospective study, 40 recently diagnosed Graves’ disease patients with proptosis, 40 recently diagnosed Graves’ disease patients without GO and 30 healthy individuals with similar demographic characteristics were included. Serum thiol-disulfide (SH-SS) measurements were performed. Eye examinations were performed by a single ophthalmologist to check for the presence of GO, and proptosis values were recorded with a Hertel exophthalmometer. Results: Total SH values were lower in the group with proptosis than in the other groups (p < 0.05). Total and native SH values were lower in patients without proptosis than in the control group (p < 0.05). Total SH, native SH and SS levels were independently associated with proptosis (p < 0.05). According to this analysis, it was found that increasing SS and decreasing total and native SH levels increased the probability of proptosis by 24.4%, 32.7% and 32.4%, respectively. Conclusion: A decrease in SH, which is a natural antioxidant that protects the body against oxidative stress, and an increase in SS are important signs of oxidative damage. Proptosis and SH-SS are closely related in GO. This may help us detect GO and proptosis in Graves’ patients. It can also assist in developing new options for preventing and treating GO.

Abstract Background Telogen effluvium is the most common form of non-scarring alopecia characterized by diffuse hair loss. Ischemia-modified albumin is a marker of oxidative stress and inflammation. Objective The aim of this study was to compare the levels of ischemia-modified albumin of telogen effluvium patients with healthy controls. Methods Ninety-one patients diagnosed with telogen effluvium and 35 healthy volunteers were included in the study. Serum ischemia-modified albumin level was determined by a fast-colorimetric method, and albumin cobalt binding test. The results were evaluated statistically. Results There was no statistically significant difference between the serum albumin values of patient and control groups (p = 0.739). Serum ischemia-modified albumin values were significantly higher in the patients with telogen effluvium than healthy controls (p < 0.001). Study limitations Body mass index values of the patient and control groups could not be calculated. Conclusions To the best of the authors’ knowledge, this is the first clinical study to investigate the role of oxidative stress in the pathogenesis of telogen effluvium using ischemia-modified albumin as a biomarker. Based on the results of the present study, it can be considered that oxidative stress plays an important role in the pathogenesis of telogen effluvium. There is a need for further studies to support the results of this study, to demonstrate the possible effects of oxidative stress, and to investigate the other oxidative stress markers in the pathogenesis of telogen effluvium.

Resumo Justificativa: O objetivo principal do estudo foi investigar o efeito de exposição à radiação ionizante de baixa dose nos níveis de homeostase tiol/dissulfeto e de albumina modificada por isquemia. O objetivo secundário foi comparar os níveis de homeostase tiol/dissulfeto e albumina modificada por isquemia entre indivíduos expostos à radiação ionizante de baixa dose nas áreas de procedimentos anestésicos, dentro e fora da sala de cirurgia. Método: O estudo incluiu um total de 90 voluntários com idades entre 18 e 65 anos, 45 profissionais que trabalhavam em ambiente de exposição potencial a radiação (Grupo Exposto) e 45 profissionais que trabalhavam em ambiente sem exposição à radiação (Grupo Controle). Foram medidos os níveis de tiol nativo, tiol total, dissulfeto, albumina e albumina modificada por isquemia. O Grupo Exposto era constituído por profissionais expostos a radiação fora da sala de cirurgia - Grupo sala de cirurgia (-) e na sala de cirurgia - Grupo sala de cirurgia (+). Resultados: Os níveis de albumina, tiol nativo e total foram significantemente mais baixos nos participantes expostos à radiação em área de realização de anestesia, e nenhuma diferença estatisticamente significante foi encontrada para os níveis de dissulfeto e albumina modificada por isquemia. No Grupo exposto sala de cirurgia (-), os valores de tiol nativo e tiol total foram significantemente mais baixos quando comparados ao Grupo sala de cirurgia (+). Conclusões: Os profissionais expostos à radiação em área de realização de anestesia devem ser conscientizados quanto ao perigo do estresse oxidativo após exposição à radiação ionizante de baixa dose e medidas cabíveis devem ser instituídas.

Abstract Background: The primary objective of this study was to investigate the effect of low dose ionizing radiation exposure on thiol/disulfide homeostasis and ischemia modified albumin levels. The secondary objective is to compare thiol/disulfide homeostasis and ischemia modified albumin levels among the personnel exposed to low dose ionizing radiation in anesthesia application areas, in and out of the operation room. Methods: The study included a total of 90 volunteers aged between 18 and 65 years old, with 45 personnel working in a setting with potential for radiation exposure (Exposed Group) and 45 personnel in a setting without radiation exposure (Control Group). Their native thiol, total thiol, disulphide, albumine and IMA levels were measured. Exposed group included personnel who were exposed to radiation outside the operating room - Operation room (−) Group and inside the operating room - Operation room (+) Group. Results: Albumin, native and total thiol levels were significantly lower in the participants exposed to radiation in the anesthesia application area; no statistically significant difference was found in terms of disulfide and ischemia modified albumin levels. In the Operation room (−) Group exposed to radiation, native thiol and total thiol values were significantly lower compared to the Operation room (+) Group. Conclusion: Awareness of being in danger of oxidative stress should be established in personnel exposed to radiation in the anesthesia application area following low dose ionizing radiation exposure, and the necessary measures should be taken.

Abstract Objective: To investigate the effect of continuous lung ventilation with low tidal volume on oxidation parameters, such as thiol/disulphide homeostasis and albumin-adjusted ischemia-modified albumin (AAIMA), during cardiopulmonary bypass (CBP) in coronary artery bypass grafting (CABG). Methods: Seventy-four patients who underwent elective CABG with CPB were included in the study. Blood samples were taken in the preoperative period, 10 minutes after CPB, and six and 24 hours postoperatively. Patients were assigned to the continuous ventilation group (Group 1, n=37) and the non-ventilated group (Group 2, n=37). The clinical characteristics, thiol/disulphide homeostasis, ischemia-modified albumin (IMA), and AAIMA levels of the patients were compared. Results: A significant difference was found between the groups regarding native thiol, total thiol, and IMA levels at the postoperative 24th hour (P=0.030, P=0.031, and P=0.004, respectively). There was no difference between the groups in terms of AAIMA. AAIMA levels returned to preoperative levels in Groups 1 and 2, at the 6th and 24th postoperative hours, respectively. Length of hospital stay was significantly shorter in Group 1 (P<0.001) than in Group 2. Conclusion: Continuous ventilation during CPB caused an increase in native and total thiol levels, an earlier return of AAIMA levels, and shorter hospital stay. Continuous ventilation may reduce the negative effects of CPB on myocardium (Table 2, Figure 1, and Reference 31).

The aim of this study is to evaluate a novel oxidative stress marker (thiol-disulphide homeostasis) in paediatric sepsis and to determine their effects on the prognosis of sepsis. Patients diagnosed with sepsis (n= 38) and healthy controls (n= 40) were incorporated in the study. Total thiol, native thiol, disulphide, disulphide/total thiol, disulphide/native thiol, and native thiol /total thiol levels were measured in the sepsis and control groups. Additionally, the parameters were compared between survivors and non-survivors in the sepsis group. The levels of hemoglobin, white blood cell, platelet, lactate, and C-reactive protein were measured in patients with sepsis at diagnosis. The paediatric risk of mortality and paediatric logistic organ dysfunction scores of the patients were used to estimate the disease severity. The plasma thiol levels of the patients with sepsis were significantly lower than the control group (p < 0.001). This study showed that thiol/disulphide homeostasis is abnormal in children with sepsis in Paediatric Intensive Care Unit.

Objetivo. Evaluar un novedoso marcador del estrés oxidativo (la homeostasis de tiol /disulfuro) en la sepsis pediátrica y determinar sus efectos sobre el pronóstico de esta afección. Métodos. En el estudio, se incluyeron pacientes con diagnóstico de sepsis y controles sanos. Se midieron las concentraciones de tiol total, tiol nativo, disulfuro, disulfuro /tiol total, disulfuro /tiol nativo y tiol nativo/tiol total en los grupos con sepsis y de referencia. Se compararon los parámetros entre los supervivientes y los no supervivientes del grupo con sepsis. Se midieron las concentraciones de hemoglobina, leucocitos, trombocitos, lactato y proteína C-reactiva en los pacientes con sepsis al momento del diagnóstico. Se utilizaron el puntaje de riesgo de mortalidad pediátrico (Pediatric Risk of Mortality, PRISM) y el puntaje de disfunción orgánica (Pediatric Logistic Organ Dysfunction, PELOD) para estimar la gravedad de la enfermedad. Resultados. En el grupo con sepsis se incluyó a 38 pacientes y en el de referencia, a 40 niños sanos. Las concentraciones plasmáticas de tiol en los pacientes con sepsis fueron significativamente inferiores que las del grupo de referencia (p < 0,001). Conclusión. La homeostasis de tiol/disulfuro fue anormal en los niños con sepsis en la unidad de cuidados intensivos pediátricos.

Abstract: We studied dynamic thiol/disulphide homeostasis, an indicator of oxidative stress, to investigate the effects of newly initiated exercise training on sedentary obese adults. Seventeen sedentary obese adults and 15 normal-weight controls were included in the sample for this study. The obese adults were given a physical exercise training program that lasted twelve weeks. Before and after the exercise training program, blood samples were collected, and serum thiol/disulphide parameters were measured by using a novel technique. Before the start of the exercise training, it was observed that thiol/disulphide homeostasis was impaired, and this impairment was positively correlated with body mass index in sedentary obese adults because of the higher reactive oxygen species production in adipose tissue. However, while the obese participants’ body mass index significantly decreased, the thiol/disulphide homeostasis parameters in the obese adults did not change over time as calculated at the baseline and compared to the calculation after the twelve weeks of exercise training. Despite a decrease in body mass index that occurred after the twelve weeks of exercise training, there was a lack of improvement in the obesity-induced impairment of thiol/disulphide homeostasis, which suggests that a newly initiated exercise training program may lead to oxidative stress.

ABSTRACT Objectives The aim of this prospective clinical study was to investigate variations in a novel oxidative stress marker (thiol/disulphide homeostasis) in men who underwent transrectal ultrasound guided prostate biopsy (TRUSB). Materials and Methods A total of 22 men undergoing TRUSB of the prostate were enrolled in the study. Patients with abnormal digital rectal examination and/or total prostate specific antigen (PSA) over 4ng/mL underwent TRUSB with 12 cores. Serum samples were obtained before and just after the procedure to evaluate the possible changes in thiol/disulphide homeostasis. Mean age, total PSA and free PSA, prostate volume and histopathological data were also recorded. Results Mean age of the study population was 65.05±8.89 years. Significant decreases in native and total thiol levels were documented after the biopsy procedure. However, serum disulphide levels and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios did not significantly change after TRUSB. No correlation was observed between oxidative parameters and total PSA and free PSA levels, prostate volume and histopathology of the prostate. However, mean patient age was significantly correlated with mean native and total thiol levels. Conclusion Significant decreases in serum native and total thiol levels related to the prostate biopsy procedure suggest that TRUSB causes acute oxidative stress in the human body. Since our trial is the first in the current literature to investigate these oxidative stress markers in urology practice, additional studies are warranted.

Abstract: Purpose: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. Methods: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. Results: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. Conclusions: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.

OBJETIVO: O estresse oxidativo demonstrou contribuir para a patogênese de doenças pulmonares inflamatórias agudas e crônicas. Nosso objetivo foi avaliar o estado oxidante/antioxidante de crianças com bronquiolite aguda por meio de mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. MÉTODOS: As crianças com bronquiolite aguda encaminhadas para o Departamento de Emergência Pediátrica do hospital universitário entre janeiro e abril 2012 foram comparadas a controles saudáveis de mesma idade. Os pacientes com bronquiolite aguda tiveram essa doença classificada como leve e moderada. O estado oxidante e antioxidante foi avaliado pela mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. RESULTADOS: Foram incluídas 31 crianças com bronquiolite aguda com idade de três meses a dois anos e 37 crianças saudáveis. O estado oxidante total (EOT) foi maior em pacientes com bronquiolite aguda do que no grupo de controle (5,16±1,99 µmol H2O2 em comparação a 3,78±1,78 µmol H2O2 [p = 0,004]). A capacidade antioxidante total (CAT) foi significativamente menor em crianças com bronquiolite que no grupo de controle (2,51±0,37 µmol Trolox equivalente/L em comparação a 2,75±0,39 µmol Trolox Eqv/L) (p = 0,013). Os pacientes com bronquiolite moderada apresentaram níveis de EOT mais elevados que os com bronquiolite leve e os do grupo de controle (p = 0,03, p < 0,001). Os pacientes com bronquiolite moderada apresentaram níveis de IEO mais elevados que os do grupo de controle (p = 0,015). O nível de saturação de oxigênio de pacientes com bronquiolite foi inversamente correlacionado ao nível de EOT (r = -0,476, p < 0,05). CONCLUSÃO: O equilíbrio entre os sistemas oxidante e antioxidante é interrompido em crianças com bronquiolite moderada, indicando que o fator de estresse poderá ter um papel na patogênese da doença.

OBJECTIVE: Oxidative stress has been shown to contribute to the pathogenesis of acute and chronic lung inflammatory diseases. This article aimed to evaluate the oxidant/antioxidant status of children with acute bronchiolitis through the measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. METHODS: Children with acute bronchiolitis admitted to the pediatric emergency department of a university hospital between January and April of 2012 were compared with agematched healthy controls. Patients with acute bronchiolitis were classified as mild and moderate bronchiolitis. Oxidative and antioxidative status were assessed by measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. RESULTS: Thirty-one children with acute bronchiolitis aged between 3 months and 2 years, and 39 healthy children were included. Total oxidative status (TOS) was higher in patients with acute bronchiolitis than the control group (5.16±1.99 µmol H2O2 versus 3.78±1.78 µmol H2O2 [p = 0.004]). Total antioxidant capacity (TAC) was lower in children with bronchiolitis than the control group (2.51±0.37 µmol Trolox eqv/L versus 2.75±0.39 µmol Trolox eqv/L [p = 0.013]). Patients with moderate bronchiolitis presented higher TOS levels than those with mild bronchiolitis and the control group (p = 0.03, p < 0.001, respectively). Patients with moderate bronchiolitis had higher oxidative stress index levels than the control group (p = 0.015). Oxygen saturation level of bronchiolitis patients was inversely correlated with TOS (r = -0.476, p < 0.05). CONCLUSION: The balance between oxidant and antioxidant systems is disrupted in children with moderate bronchiolitis, which indicates that this stress factor may have a role in the pathogenesis of the disease.

OBJETIVOS: Estudar o efeito do fumo passivo sobre o estado plasmático oxidativo e antioxidativo em pré-escolares fumantes passivos e compará-los com controles. MÉTODOS: Trinta e quatro pré-escolares fumantes passivos (cinco a 50 cigarros/dia) (grupo de estudo) e 32 controles que nunca estiveram expostos à fumaça de cigarro foram escolhidos aleatoriamente entre crianças de 4 a 6 anos. Foram determinados os níveis de cotinina urinária e de indicadores do estado oxidativo e antioxidativo, isto é, estado oxidante total (EOT), capacidade antioxidante total (CAT) e índice de estresse oxidativo (IEO). RESULTADOS: A média do consumo ambiental de cigarros foi de 22±13 cigarros por dia nas crianças fumantes passivas. Os níveis médios de cotinina urinária foram 77,6±41,4 ng/mL e 11,9±2,3 ng/mL nos grupos de estudo e controle, respectivamente (p < 0,001). Os níveis médios da CAT plasmática foram 0,95±0,13 mmol equivalente de Trolox/L e 1,01±0,09 mmol equivalente de Trolox/L, respectivamente (p = 0,039). Os níveis médios de EOT plasmático foram 28,6±7,9 µmol H2O2 equivalente/L e 18,5±6,3 µmol H2O2 equivalente/L, respectivamente (p < 0,001). Os níveis médios de IEO foram 3,08±0,98 unidade arbitrária e 1,84±0,64 unidade arbitrária, respectivamente (p < 0,001). Uma pequena quantidade de fumaça de cigarro (cinco a 10 cigarros/dia) causa estresse oxidativo considerável. Não houve correlações significativas entre o número de cigarros consumidos e os níveis de estado oxidante e de IEO. CONCLUSÕES: O tabagismo passivo é um potente oxidante em pré-escolares. Seus efeitos deletérios não se limitam apenas tabagismo passivo pesado, mas também ocorrem com a exposição a pequenas quantidades de fumaça.

OBJECTIVES: To study the effect of passive cigarette smoking on plasma oxidative and antioxidative status in passive smoking preschool children and to compare them with controls. METHODS: Thirty-four passive smoking (five to 50 cigarettes per day) preschool children (study group) and 32 controls who had never been exposed to cigarette smoke were randomly chosen from children aged from 4 to 6 years. Urinary cotinine and plasma indicators of oxidative and antioxidative status, i.e., total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI), were determined. RESULTS: Mean environmental cigarette consumption was 22±13 cigarettes per day in passive smoking children. Mean urinary cotinine levels were 77.6±41.4 ng/mL and 11.9±2.3 ng/mL in the study and control groups, respectively (p < 0.001). Mean plasma TAC levels were 0.95±0.13 mmol Trolox equivalent/L and 1.01±0.09 mmol Trolox equivalent/L, respectively (p = 0.039). Mean plasma TOS levels were 28.6±7.9 µmol H2O2 equivalent/L and 18.5±6.3 µmol H2O2 equivalent/L, respectively (p < 0.001). Mean OSI levels were 3.08±0.98 arbitrary units and 1.84±0.64 arbitrary units, respectively (p < 0.001). A small amount of cigarette smoke (five to 10 cigarettes per day) causes considerable oxidative stress. There were significant correlations between number of cigarettes consumed and oxidant status and OSI levels. CONCLUSIONS: Passive smoke is a potent oxidant in preschool children. Its deleterious effects are not limited just to heavy passive smoking, but also occur with exposure to small amounts of smoke.

Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. We aimed to determine total antioxidant capacity (TAC), total peroxide, malondialdehyde and catalase levels in plasma samples, and calculation of oxidative stress index (OSI) in patients with brucellosis to evaluate their oxidative status using a novel automated method. Sixty-nine patients with brucellosis and 69 healthy control subjects were included in the present study. Plasma levels of total peroxide and malondialdehyde were significantly increased in patients as compared with healthy controls (p<0.001 and p<0.001, respectively). In contrast, TAC level was significantly lower in patients as compared with controls (p<0.001). There was no statistically significant difference between the catalase results of the two groups (p>0.05). OSI level was significantly increased in patients as compared with healthy controls (p<0.001). In conclusion, oxidants were increased and antioxidants were decreased in patients with brucellosis. Oxidative stress was increased in patients with brucellosis.

OBJETIVO: Determinar se a fita de DNA de leucócitos mononucleares endógenos é alvo de fototerapia. MÉTODOS: O estudo incluiu 65 recém-nascidos a termo com idades entre 3 e 10 dias que haviam sido expostos a fototerapia intensiva (n = 23) ou convencional (n = 23) por pelo menos 48 horas devido à icterícia neonatal, além de um grupo controle (n = 19). Dano ao DNA foi avaliado por eletroforese alcalina em gel de célula única (ensaio cometa). A capacidade antioxidante total plasmática e os níveis de estado oxidativo total também foram medidos, e a correlação entre danos ao DNA e estresse oxidativo foi investigada. RESULTADOS: Os valores médios de escores de danos ao DNA nos grupos de fototerapia intensiva e convencional foram significativamente maiores do que os do grupo controle (p < 0,001). Os valores médios e desvio padrão foram 32 (9), 28 (9), 21 (7) unidades arbitrárias, respectivamente. Os níveis de estado oxidativo nos grupos de fototerapia intensiva e convencional foram significativamente maiores do que os do grupo controle (p < 0,005). Os valores médios (desvio padrão) foram 18, 1 (4,2), 16.9 (4,4), 13,5 (4,2) µmol H2O2 equivalente/L, respectivamente. De maneira semelhante, os níveis de estresse oxidativo nos grupos de fototerapia intensiva e convencional foram significativamente maiores do que os do grupo controle (p = 0,041). A capacidade antioxidante total plasmática e os níveis de bilirrubina total não diferiram entre os grupos (p > 0,05). Não houve correlações significativas entre escores de danos ao DNA e bilirrubina, estado oxidante total e níveis de estresse oxidativo entre os grupos de fototerapia (p > 0,05). CONCLUSÕES: Tanto a fototerapia intensiva quanto a convencional causam danos ao DNA dos leucócitos mononucleares endógenos em recém-nascidos a termo com icterícia.

OBJECTIVE: Our aim was to determine whether endogenous mononuclear leukocyte DNA strand is a target of phototherapy. METHODS: The study included 65 term infants aged between 3-10 days that had been exposed to intensive (n = 23) or conventional (n = 23) phototherapy for at least 48 hours due to neonatal jaundice, and a control group (n = 19). DNA damage was assayed by single-cell alkaline gel electrophoresis (comet assay). Plasma total antioxidant capacity and total oxidant status levels were also measured, and correlation between DNA damage and oxidative stress was investigated. RESULTS: Mean values of DNA damage scores in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p < 0.001). Mean values and standard deviation were 32 (9), 28 (9), 21 (7) arbitrary unit, respectively. Total oxidant status levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.005). Mean (standard deviation) values were 18.1 (4.2), 16.9 (4.4), 13.5 (4.2) µmol H2O2 equivalent/L, respectively. Similarly, oxidative stress index levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.041). Plasma total antioxidant capacity and total bilirubin levels did not differ between the groups (p > 0.05). There were no significant correlations between DNA damage scores and bilirubin, total oxidant status and oxidative stress levels in either phototherapy group (p > 0.05). CONCLUSIONS: Both conventional phototherapy and intensive phototherapy cause endogenous mononuclear leukocyte DNA damage in jaundiced term infants.

OBJETIVO: Avaliar o efeito da fototerapia no estado oxidante e antioxidante no soro de recém-nascidos a termo com hiperbilirrubinemia. MÉTODO: Trinta e quatro recém-nascidos a termo com idades entre 3 e 10 dias submetidos a fototerapia foram avaliados. O estado antioxidante do soro foi determinado pela capacidade antioxidante total e por componentes antioxidantes individuais: vitamina C, ácido úrico, albumina, concentração de tiol e bilirrubina total. O estado oxidante foi avaliado através do estado oxidante total, índice de estresse oxidativo e componentes oxidantes individuais: malondialdeído e níveis de hidroperóxido lipídico. RESULTADOS: As concentrações de vitamina C, ácido úrico, bilirrubina total e malondialdeído foram significativamente mais baixas, enquanto que o estado oxidante total, níveis de hidroperóxido lipídico e o índice de estresse oxidativo foram significativamente maiores após a fototerapia (p < 0,05). Houve correlações positivas significativas entre a bilirrubina sérica total e a concentração de malondialdeído (r = 0,434, p = 0,001). CONCLUSÕES: Embora a concentração de malondialdeído tenha diminuído após a fototerapia, esta exerce um efeito negativo sobre as diversas partes do sistema de defesa oxidante/antioxidante em recém-nascidos a termo ictéricos, expondo-os a um possível estresse oxidativo.

OBJECTIVE: To assess the effect of phototherapy on serum oxidant and antioxidant status in hyperbilirubinemic full-term newborns. METHOD: Thirty-four full-term infants from 3 to 10 days of age exposed to phototherapy were studied. The serum antioxidant status was assessed by measuring the total antioxidant capacity (TAC) and individual antioxidant components: vitamin C, uric acid, albumin, thiol contents and total bilirubin. The oxidant status was assessed by determining the total oxidant status (TOS), oxidative stress index (OSI) and individual oxidant components: malondialdehyde (MDA), and lipid hydroperoxide levels. RESULTS: Vitamin C, uric acid, total bilirubin and MDA concentration were significantly lower, whereas serum TOS, lipid hydroperoxide and OSI levels were significantly higher after phototherapy (p < 0.05). There were significant positive correlations between serum total bilirubin and MDA (r = 0.434, p = 0.001). CONCLUSIONS: Although the MDA level was reduced after phototherapy, phototherapy has a negative impact on numerous parts of the oxidant/antioxidant defense system in jaundiced full-term newborns, exposing them to potential oxidative stress.