Montes-Cortes Dh

Antioxidants decrease reperfusion induced arrhythmias in myocardial infarction with ST-elevation.

In myocardial infarctions with ST-segment elevation, ischemia followed by reperfusion (IR) leads to arrhythmia, myocardial stunning and endothelial dysfunction injury by reactive oxygen species (ROS). To determine the impact of ROS, we examined the effect of antioxidant vitamins on biochemical changes and arrhythmias induced by reperfusion before and after therapeutic thrombolysis (Actilyse). As compared with those receiving placebo, in individuals who received antioxidants, there was a significant decrease in premature ventricular beats (100% vs 38%), atrial fibrillation (44% vs 6%), ventricular tachycardia (31% vs 0%), first-degree atrial-ventricular block (44% vs 6%), plasma malondialdehyde at the first hour after initiation of thrombolysis (1.07 +/- 0.10 vs 0.53 +/- 0.10 nmols plasma malondialdehyde/mg protein) and circulating neutrophils after 24 hr after reperfusion. The antioxidant capacity of plasma was increased from 1.89 +/- 0.15 to 3.00 +/- 0.31 units/mg protein and paraoxonase-1 rose from 0.77 +/- 0.08 to 1.27 +/- 0.11 nmol/min/mg protein. These findings suggest that antioxidants might be useful as adjuvants in controlling reperfusion induced arrhythmias following therapeutic alteplase thrombolysis.

Chemical and functional changes of human insulin by in vitro incubation with blood from diabetic patients in oxidative stress

Oxidative stress damage to biomolecules has been implicated in several diseases including diabetes mellitus. In the present study, we investigated the effect of oxidative stress in whole blood (WB) from diabetic patients (n = 60) on recombinant human insulin. Insulin was incubated with WB obtained from diabetic patients (DP) who had hyperglycemia (>300 mg/dL) or from 41 healthy volunteers (HV). Whole blood of DP, unlike WB of HV, induced higher values of formazan (142%), dityrosines (279%), and carbonyls (58%) in the insulin residues. Interestingly, the insulin modified by WB of DP showed less hypoglycemic activity in rat (30%) in comparison with insulin incubated with WB of HV. The incubation of insulin in WB from DP induces chemical changes in insulin and a decrease in its biological activity, events that might be associated with the high levels of oxidative stress markers found in the plasma of these patients.

Impact of intestinal mannitol on hyperammonemia, oxidative stress and severity of hepatic encephalopathy in the ED

ABSTRACT Hyperammonemia results from hepatic inability to remove nitrogenous products generated by protein metabolism of intestinal microbiota, which leads to hepatic encephalopathy (HE) in chronic liver disease (CLD). In ammonium neurotoxicity, oxidative stress (OxS) plays a pathogenic role. Our objective was to evaluate if intestinal mannitol is as effective and safe as conventional treatment for diminishing hyperammonemia, OxS, and HE in patients with CLD. Material and methods We included 30 patients with HE classified by “Haven Criteria for Hepatic Encephalopathy”. They were randomized into two groups: 1) Mannitol Group (MG) with mannitol 20% administered into the intestine by an enema, 2) conventional group (CG) with lactulose 40 g enema both substances were diluted in 800 mL of double distilled solution every 6 h; all patients received neomycin. We evaluated ammonia concentration, plasma oxidative stress, HE severity, intestinal discomfort and adverse effects. Results Hyperammonemia (171 ± 104 vs 79 ± 49 &mgr;mol ammonia/L, p < 0.01), and oxidative stress (MDA 29 vs 27%, formazan 15 vs 11%, carbonyls 16 vs 9% and dityrosines 10 vs 5%) were reduced in MG and CG respectively. The HE severity decreased by two degrees compared to baseline values in both groups. Intestinal discomfort and electrolyte plasma alterations were less frequent (p < 0.05) in MG than CG. Conclusions Intestinal mannitol is as effective and safe as conventional treatment for reducing hyperammonemia, oxidative stress, and hepatic encephalopathy of CLD patients in the emergency room. Likewise, mannitol is better tolerated than conventional treatment.

Cuestionario de funcionalidad para esclerosis sistémica (SySQ): validación en español del original en alemán y su relación con la enfermedad y la calidad de vida

OBJECTIVE Translation, transculturation and validity of the self-administered questionnaire for functionality (Systemic Sclerosis Questionnaires [SySQ]) for use in Spanish patients with systemic sclerosis and its relationship to the severity of the disease and to quality of life. PATIENTS AND METHODS We conducted an observational analytical study to perform a cross-cultural validation of the self-administered questionnaire on functionality in scleroderma. The validity of the form and content was evaluated by an expert panel. The method included: a) adaptation into Spanish of the construct for translation and back translation, and transculturation; b) internal consistency with the SySQ (Cronbachs alpha), and c) reproducibility was assessed taking into account all occasions in which the test was performed with Cohens kappa. Additionally, we calculated the Spearman correlation coefficient with the Medsger severity scale, Health Assessment Questionnaire score and SF-36 score. RESULTS We included 70 patients with systemic sclerosis: age 17-78 (51±12) years, 65 (93%) were women, diffuse/limited subtype 64/36%, disease duration of 0.5-40 years. Optimal internal consistency for all categories of the final version of SySQ (Cronbachs α of 0.961) and intraobserver reliability in 2 tests over a 2-week interval (Cohens kappa coefficient 0.618) and optimal interobserver reliability in 2 tests on the same day (Cohens kappa coefficient 0.911). Moderate correlation between functionality by SySQ and by Health Assessment Questionnaire (r=0.573, P<.0001). Inverse correlation between SySQ and quality of life mental health domain SF-36 (r=-0.435, P<.001) and physical domain SF-36 (r=-0.638, P<.001). Medsger severity scale (tendon, heart, lung, vascular) also showed significant correlation with SySQ. CONCLUSIONS SySQ in this validated Spanish version is a suitable instrument to measure functional status in patients with systemic sclerosis. Reduced functionality is related to greater tendon and peripheral vascular involvement and to a poorer quality of life.