Aumento de estresse oxidativo no sangue de pacientes com ostomia / Increased oxidative stress in the blood of ostomy patients

ABSTRACT BACKGROUND: Ostomy is a surgical procedure that creates a stoma that aims to construct a new path for the output of feces or urine. The relationship of oxidative stress (OxS) markers in patients with ostomy is still poorly described. OBJECTIVE: The present study was aimed at investigating the changes in oxidative stress parameters in peripheral blood collected from ostomy patients when compared with a healthy control group. METHODS: It was evaluated 29 ostomy patients and 30 healthy control patients. The oxidative stress parameters evaluated were: lipid peroxidation [lipid hydroperoxide (LPO), 8-isoprostane (8-ISO) and 4-hydroxynonenal (4-HNE)], protein oxidation and nitration [carbonyl and 3-nitrotyrosine (3-NT)] and DNA oxidation [8-hydroxy-2'-deoxyguanosine (8-OHDG)] in serum from ostomy patients compared to health controls. RESULTS: The data showed an increase of LPO, 8-ISO, 4-HNE, 3-NT and 8-OHDG in serum collected from ostomy patients when compared to healthy controls. CONCLUSION: The findings support the hypothesis that ostomy triggers the oxidative stress observed in the blood collected from these patients.

RESUMO CONTEXTO: Ostomia é um procedimento cirúrgico que cria um estoma com objetivo de construir um novo caminho para a saída das fezes ou urina. A relação dos marcadores de estresse oxidativo em pacientes ostomizados ainda é pouco descrita. OBJETIVO: O presente estudo tem como objetivo investigar as alterações dos parâmetros de estresse oxidativo em sangue de pacientes ostomizados comparados a controles saudáveis. MÉTODOS: Foram avaliados 29 pacientes ostomizados e 30 controles saudáveis. Os parâmetros de estresse oxidativo avaliados foram: peroxidação lipídica [hidroperóxido de lipídio (LPO), 8-isoprostano (8-ISO) e 4-hidroxinonenal (4-HNE)], oxidação e nitração de proteínas [carbonila e 3-nitrotirosina (3-NT)] e oxidação do DNA [8-hidroxi-2'-desoxiguanosina (8-OHDG)] em soro de pacientes ostomizados comparados a controles saudáveis. RESULTADOS: Os dados mostraram um aumento de LPO, 8-ISO, 4-HNE, 3-NT e 8-OHDG em soro de pacientes ostomizados em comparação a controles saudáveis. CONCLUSÃO: Os achados sustentam a hipótese de que a ostomia desencadeia o estresse oxidativo observado no sangue coletado destes pacientes.

Radioiodine-induced oxidative stress in patients with differentiated thyroid carcinoma and effect of supplementation with vitamins C and E and selenium (antioxidants)

ABSTRACT Objective The objective of this study, in addition to confirming that therapy with 131I causes oxidative stress, was to evaluate the effect of supplementation with vitamins C and E and selenium on this phenomenon by measuring plasma 8-epi-PGF2a, a marker of lipid peroxidation. Subjects and methods Forty patients with thyroid cancer submitted to thyroidectomy, who received 3.7 GBq 131I after levothyroxine withdrawal, were selected; 20 patients did not receive (control group) and 20 patients received (intervention group) daily supplementation consisting of 2000 mg vitamin C, 1000 mg vitamin E and 400 µg selenium for 21 days before 131I. Plasma 8-epi-PGF2a was measured immediately before and 2 and 7 days after 131I. Results A significant increase in plasma 8-epi-PGF2a after 131I was observed in the two groups. The concentrations of 8-epi-PGF2α were significantly higher in the control group before and 2 and 7 days after 131I. The percentage of patients with elevated 8-epi-PGF2α was also significantly higher in the control group before and after 131I. Furthermore, the increase (percent) in 8-epi-PGF2α was significantly greater in the control group (average of 112.3% versus 56.3%). Only two patients (10%) reported side effects during supplementation. Conclusions Ablation with 131I causes oxidative stress which can be minimized by the use of antioxidants.

Antioxidant supplementation decreases the cell death rate in the prostatic stromal tissue of long-term castrated rats

OBJECTIVE: The purpose of this study was to compare the effects of castration on cell death rate of the adult rat prostates and to evaluate the benefic action of alpha tocopherol supplementation to avoid apoptosis post-orchiectomy. MATERIAL AND METHODS: Thirty male Wistar rats weighing 250-300g were divided into three groups: group I - they were subjected to bilateral orchiectomy and sacrificed eight weeks after the procedure; group II - subjected to bilateral orchiectomy and alpha-tocopherol supplementation for four weeks preceding the procedure; and group III - subjected to bilateral orchiectomy and alpha-tocopherol supplementation for four weeks preceding the procedure and for eight weeks afterwards. At the end of the experiment, the prostatectomy was performed in all rats. The presence of oxidative stress was determined by assaying the blood level of 8-isoprostane and the occurrence of apoptosis was evaluated by identification of active caspase-3 through immunohistochemical analysis. RESULTS: The statistic analysis of active caspase-3 showed that in the long-term castrated group the detection was higher than in groups were the alpha-tocopherol was supplemented (p=0.007). Analysis of 8-isoprostane levels showed higher concentrations of reactive oxygen species in group I compared to other groups (p<0.05). Groups II and III presented active caspase-3 lower than in group I (p<0.05). CONCLUSION: Our exploratory analyses demonstrate a method to study the aging process and its influence on oxidative stress of prostatic tissue and cells death rate. Based on our results we can suggest that alpha tocopherol supplementation can decrease the apoptotic process as well as the oxidative stress levels induced by androgen deprivation of the prostate gland.

Impact of castration with or without alpha-tocopherol supplementation on the urethral sphincter of rats

OBJECTIVE: To analyze the impact of low levels of testosterone induced by orchiectomy and the effect of alpha-tocopherol supplementation on oxidative stress in the urethral sphincter. MATERIALS AND METHODS: Forty male Wistar rats weighing 250-300g were divided into four groups with 10 each: Sham group; Orchiectomy group: bilateral orchiectomy; Orchiectomy-pre-Tocopherol group: bilateral orchiectomy preceded by alpha-tocopherol supplementation for four weeks; Orchiectomy-full-Tocopherol group: bilateral orchiectomy with alpha-tocopherol supplementation for four weeks preceding the procedure and for eight weeks afterwards. At the protocol end, animals were euthanized and had the sphincter analyzed stereologically focusing on collagen and muscle fibers percentage. Oxidative stress levels were determined using 8-epi-PGF2. RESULTS: The 8-epi-PGF2 levels were statistically higher (p < 0.0003) in the Orchiectomy group compared to others groups while Sham and Orchiectomy-full-Tocopherol groups presented statistically similar values (p = 0.52). Collagen volumetric densities were significantly lower in Sham and Orchiectomy-full-Tocopherol groups (p < 0.022). Sham group presented statistically greater muscle fiber percent. CONCLUSION: Castration caused oxidative stress in the urethral sphincter complex, with increased collagen deposition. Alpha-tocopherol had a protective effect and its supplementation for twelve weeks provided the greatest protection.

Exhaled breath condensate analysis in chronic obstructive pulmonary disease.

The increasing focus on airway inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has led to development and evolution of tools to measure it. Direct assessment of airway inflammation requires invasive procedures, and hence, has obvious limitations. Non-invasive methods to sample airway secretions and fluids offer exciting prospects. Analysis of exhaled breath condensate (EBC) is rapidly emerging as a novel non-invasive approach for sampling airway epithelial lining fluid and offers a convenient tool to provide biomarkers of inflammation. It has definite advantages that make it an attractive and a feasible option. It is a source of mediators and molecules that are the causes or consequences of the inflammatory process. Measurement of such markers is increasingly being explored for studying airway inflammation qualitatively and quantitatively in research studies and for potential clinical applications. These biomarkers also have the potential to develop into powerful research tools in COPD for identifying various pathways of pathogenesis of COPD that may ultimately provide specific targets for therapeutic intervention. The EBC analysis is still an evolving noninvasive method for monitoring of inflammation and oxidative stress in the airways. The limited number of studies available on EBC analysis in COPD have provided useful information although definite clinical uses are yet to be defined. Evolving technologies of genomics, proteomics, and metabonomics may provide deeper and newer insights into the molecular mechanisms underlying the pathogenesis of COPD.

Effect of oxytocin infusion on luteal blood flow and progesterone secretion in dairy cattle

The objective of this study was to investigate the effects of oxytocin infusion on corpus luteum (CL) function during early to mid-diestrus by measuring luteal size (LS) and luteal blood flow (LBF) along with plasma levels of progesterone (P4) and prostaglandin metabolites (13,14-dihydro-15-keto-prostaglandin F2alpha, PGFM). On day (D) 7 of the estrus cycle (D1 = ovulation), seven cows received 100 IU of oxytocin (OXY) or placebo (PL) following a Latin square design. LS and LBF increased in both groups over time and no differences were observed between the groups. PGFM did not differ either within the groups over time or between the groups at any time point. P4 of the OXY group was higher compared to that of the the PL group 360 min after the infusion (p = 0.01) and tended to be higher at the time points 450 min, 48 h, and 72 h (all p = 0.08). Results from this study support the hypothesis that OXY is not directly involved in the mechanism(s) governing blood flow of the CL and has no remarkable effects either on luteal size or P4 and PGFM plasma levels. Further investigation is needed to elucidate the role of OXY in CL blood flow during early and late luteal phases.

Improving the reproductive efficiency of the goat: vaginal cytology and vulvar biometry as predictors of synchronized estrus/breeding time in West African dwarf goat / Mejora de la eficiencia reproductiva de la cabra: citología vaginal y biometría vulvar como predictores de la sincronización del periodo estro/crianza de cabras enanas del Oeste Africano

The characteristics of exfoliated vaginal cells and vulvar biometry following estrus synchronization via two injections of 5mg Lutalyse® administered 7 days apart were investigated with the aim of their possible use to predict estrus in six adult WAD does. Four adult WAD bucks recently passed as satisfactory potential breeders were also involved in the study. The animals were maintained on 12 percent crude protein concentrate, greens and fresh water ad libitum. All measurements in the does were taken at an interval of 24 hours for six days beginning with the day of 2nd Lutalyse® injection. The does were introduced to the bucks 48 hours after the 2nd dose of Lutalyse® and separated from them after the 6th day. The 72-96 and 96-120 hours vaginal smears of 5 does (i.e. 83.3 percent) were characteristic during the study. They were positive for sperm cells and showed sharp increase in the degree of clumping of exfoliated cells. During these periods also, the differences in the percentage of superficial cells (i.e. 77.4 +/- 1.05 and 56.4 +/- 0.77) over other epithelial cells (12.2 +/- 0.38 and 1.30 +/- 0.82) respectively were significant (P<0.05). The percentage leucocytes also varied during the study but increased sharply during 96 -120 hours. The result on vulvar biometry between 0-72 hours and the period during which mating occurred (i.e. 72-120 hours) was not significant (P>0.05). All does with vaginal smear positive for sperm cells were confirmed pregnant at day 60 following mating by ultrasonography. The results of this study show that two injections of 5mg Lutalyse® 7 days apart will produce fertile estrus in the WAD doe. In conclusion, a careful evaluation of 24 hourly exfoliated vaginal cells will enhance synchronized estrus detection in WAD goat and improve their reproductive efficiency.

Fueron investigadas en seis cabras WAD hembras adultas, las características de las células vaginales exfoliadas y la biometría vulvar, tras una sincronización de estros a través de dos inyecciones de 5 mg de Lutalyse ®, administrados cada 7 días, con el fin de hacer posible el uso y predecir el estro. También participaron en este estudio cuatro machos adultos WAD probados recientemente como potenciales reproductores. Los animales fueron alimentados con un concentrado de proteína cruda de 12 por ciento, pastos y agua ad libitum. Las medidas en las cabras fueron tomadas con un intervalo de 24 horas, durante 6 días, a contar de la segunda inyección Lutalyse ®. Después de 48 horas de la 2 dosis de Lutalyse ® las cabras fueron cruzadas, y separadas de los machos después del 6 día. Fue realizado el estudio en frotis vaginales de 72-96 horas y de 96-120 horas, en 5 hembras (83,3 por ciento). Estos frotis fueron positivos para las células espermáticas y mostraron fuerte aumento en el grado de aglutinación de células de descamación. Durante estos períodos, las diferencias en el porcentaje de células superficiales (77,4 +/- 1,05 y 56,4 +/- 0,77) sobre las células epiteliales de otros (12,2 +/- 0,38 y 1,30 +/- 0,82) fueron significativas (P <0,05). También varió el porcentaje de leucocitos durante el estudio, pero aumentó considerablemente durante el periodo de 96-120 horas. El resultado de biometría vulvar entre 0-72 horas y del período durante el cual se produjo el apareamiento (72-120 horas) no fue significativa (P> 0,05). Todas las hembras con frotis vaginal positivo para células espermáticas, se les confirmó la preñez por ecografía, a los 60 días posterior al apareamiento. Los resultados de este estudio mostraron que dos inyecciones de 5 mg Lutalyse ® con 7 días de diferencia produce estro fértil en la cabra WAD. En conclusión, una evaluación cuidadosa de las células vaginales exfoliadas a las 24 horas, mejorará la detección del estro en cabras WAD y su eficiencia...