Efecto de una dieta hipocalórica en el estrés oxidativo en sujetos obesos sin prescripción de ejercicio y antioxidantes / Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants

Fundamento y objetivo: La obesidad se caracteriza por un aumento generalizado de tejido adiposo, alta producción de adipocitocinas y presencia de estrés oxidativo sistémico. El objetivo de este estudio fue evaluar los cambios generados en el estrés oxidativo y los parámetros antropométricos en sujetos obesos por la prescripción de una dieta hipocalórica en combinación con ejercicio aeróbico moderado y suplementación con antioxidantes. Pacientes y métodos: El daño oxidativo fue determinado en el plasma de 30 sujetos con normopeso y 30 sujetos obesos. Se consideraron 3 grupos de tratamiento: dieta hipocalórica (DH), DH más ejercicio aeróbico moderado (DHE), y DHE más antioxidantes (DHEA). Se determinaron biomarcadores de daño oxidativo (compuestos reactivos al ácido tiobarbitúrico [CRAT], grupos carbonilo, ditirosinas) y valores de parámetros antropométricos. Resultados: Se observaron valores incrementados en biomarcadores de daño oxidativo en sujetos obesos (13.74 ± 1.2 uM, carbonilos 0,89 ± 0,04 nmoles de osazonas/mg de proteína, ditirosinas 478,9 ± 27,4 URF/mg de proteína) en comparación con sujetos con normopeso (CRAT 7,08 ± 0,8 uM, carbonilos 0,65 ± 0,04 nmoles de osazonas/mg de proteína, ditirosinas 126,3 ± 12,6 URF/mg de proteína), demostrando la presencia de un daño oxidativo. La prescripción de DH disminuyó el daño oxidativo y los parámetros antropométricos en el sujeto obeso. No se observaron efectos benéficos adicionales en estas determinaciones con los tratamientos DHE o DHEA. Conclusiones: Demostramos que una DH reduce el daño oxidativo en sujetos obesos. El estrés oxidativo es un factor importante en el desarrollo de comorbilidades en obesidad. Por lo tanto, la prescripción de una DH podría ser un punto clave en el tratamiento de la enfermedad (AU)

Background and objective: Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants. Patients and methods: Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined. Results: Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 μM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 μM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments. Conclusions: We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease (AU)

[Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants]. / Efecto de una dieta hipocalórica en el estrés oxidativo en sujetos obesos sin prescripción de ejercicio y antioxidantes.

BACKGROUND AND OBJECTIVE: Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants. PATIENTS AND METHODS: Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined. RESULTS: Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 µM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 µM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments. CONCLUSIONS: We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease.

Prevalencia de receptores hormonales y del receptor del factor de crecimiento epidérmico humano tipo 2 en pacientes mexicanas con cáncer de mama / Prevalence of hormonal receptors and human epidermal growth factor receptor 2 in Mexican female patients with breast cancer

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Testosterone metabolites mediate its effects on myocardial damage induced by ischemia/reperfusion in male Wistar rats.

The role of testosterone in cardiovascular (CV) homeostasis is in controversy, and the exact effects of testosterone on the cardiovascular system remain poorly understood. Testosterone is metabolized by aromatase into 17ß-estradiol and by 5α-reductase into dihydrotestosterone (DHT). Thus, identification of these metabolites in the heart may help to explain the controversy regarding the cardiovascular effects of testosterone. We analyzed the expression patterns of these testosterone-metabolizing enzymes and assessed the effect of its enzymatic activity inhibition on ischemia (40 min)/reperfusion (4h, I/R) via the left anterior descendent coronary artery in intact and gonadectomized male rats. Myocardial damage was measured as percentage of infarcted area vs. area at risk. Aromatase and 5α-reductase protein expression was found in the left ventricle of intact and orchidectomized rats. Exogenous testosterone had no effect on I/R induced myocardial damage in intact male rats, meanwhile exogenous testosterone protects against I/R injury in orchidectomized rats. However, enzymatic inhibition of aromatase increased myocardial damage in the presence of testosterone, while enzymatic inhibition of 5α-reductase significantly decreased the level of myocardial damage. Our results also showed that sub-chronic inhibition of 5α-reductase resulted in myocardial protection in both groups. Furthermore, in orchidectomized and intact male rats IV treatment with DHT induces a significant increase in the myocardial damage induced by I/R. Thus, the effect of testosterone on cardiovascular pathophysiology could be related, at least in part to changes in the balance of testosterone 5α-reduction and aromatization.

Arginase activity in patients with breast cancer: an analysis of plasma, tumors, and its relationship with the presence of the estrogen receptor.

BACKGROUND: Breast cancer is an important cause of cancerrelated death in women. In this pathological condition, arginase plays a role by providing ornithine as a substrate for the biosynthesis of polyamines which are important in tumor progression. The aim of this work was to determine the arginase activity in the plasma and tumors of patients with breast cancer; also, we investigated the relationship between this activity and the presence of the estrogen receptor. PATIENTS AND METHODS: We evaluated the plasma arginase activity levels in 80 women with breast cancer and 42 healthy control subjects. We also measured the arginase levels in 42 breast cancer biopsies and 42 control tissues. RESULTS: The mean activity of arginase in plasma was higher in breast cancer patients (0.78 nM/min/mg protein ± 0.04; p = 0.001) than in healthy volunteers (0.53 nM/ min/mg protein ± 0.04); however, this difference was indicative of patients in the advanced stages of the disease (n = 38, stage III; p < 0.0001). In addition, we did not find a relationship between the estrogen receptor and arginase activity. CONCLUSION: Our results show a higher arginase activity in the plasma of patients in the advanced stages of the disease, suggesting that arginase activity could serve as a possible biological marker of breast cancer progression.