Effect of an antioxidant drink on homocysteine levels in Alzheimer's patients.

BACKGROUND: A large body of evidence supports a role of oxidative stress in Alzheimer disease (AD) and in cerebrovascular disease. Blood levels of homocysteine may be increased in AD and hyperhomocysteinemia may contribute to disease pathophysiology by vascular and direct neurotoxic mechanisms. Even in the absence of vitamin deficiency, plasma total homocysteine (tHcy) concentration may be influenced by administration of polyphenols. OBJECTIVE: To determine the effect of an antioxidant beverage rich in polyphenols on the plasmatic levels of tHcy in Alzheimer's patients. DESIGN, SETTING, AND PATIENTS: A multicenter, randomized, double-blind controlled clinical trial of polyphenols supplementation in 100 subjects (52 of control group, 24 AD patients in initial phase and 24 AD patients in moderate phase) (Mini-Mental State Examination scores between 14 and 26, inclusive). Fasting plasma concentrations of tHcy, folate and vitamin B(12) were measured before (Ti) and after (Tf) the ingestion of the beverage. The study was conducted at clinical research places of the Catholic University San Antonio and University Hospital Virgen de la Arrixaca of Murcia (Spain). INTERVENTION: Participants of the three groups were randomly assigned to 2 groups of the same size: 50% treated with antioxidant beverage rich in polyphenols and 50% treated with an identical placebo beverage. Subjects consumed 1 brick (200 mL/day) of antioxidant drink or placebo drink for 8 months. RESULTS: Higher tHcy levels were observed in the AD moderate phase patients (Ti:12.65±1.21 µmol/L) than in the AD initial phase patients (Ti:9.13±1.24 µmol/L) and in the control group (Ti:9.86±0.77 µmol/L). Lower folate levels were observed in the AD moderate phase patients (Ti:8.20±1.29 ng/mL) than in the AD initial phase patients (Ti:9.41±1.56 ng/mL) and in the control group (Ti:12.32±0.67 ng/mL). Antioxidant drink vs placebo drink attenuated the tHcy increase in the control group (Tf values of 11.74±0.45 vs 15.63±1.79 µmol/L) and AD patients, especially in the moderate phase (Tf: 10.49±0.73 vs 16.58±2.73 µmol/L). CONCLUSIONS: The regular ingestion of polyphenols contained in an antioxidant beverage may decrease tHcy plasmatic concentrations in Alzheimer's patients.

Effects of hyperoxia on biomarkers of oxidative stress in closed-circuit oxygen military divers.

Oxygen toxicity is a problem in diving which can have fatal consequences in the water. When divers use closed-circuit oxygen rebreathing apparatus they are taking only oxygen 100% and this hyperoxic exposure increases the generation of reactive oxygen species (ROS) in biological tissues. The objective of the present study is to evaluate the effects of hyperoxia on biomarkers of oxidative stress in closed-circuit oxygen military divers. Fifteen professional divers of Spanish Navy Diving Centre participated in a training program which consisted of one-hour immersion at seven metres of depth breathing oxygen 100% with closed-circuit oxygen rebreathing apparatus. The training went on two or three times per week for the first six weeks and once a week for the last six weeks. Serum total antioxidant status (TAS), levels of glutathione peroxidase (GPx), nitrates (NO3(-)) and urinary concentrations of 15-isoprostane F2t were measured. The results show that TAS decreased significantly after 6 weeks (mean 1.38 versus 1.23 mmol/l), with a slight increase at the end (mean 1.31 mmol/l). GPx and F2-isoprostanes were significantly lower after 6 and 12 weeks and NO3(-) was significantly lower after 6 weeks and remained unchanged until the end. In summary, professional divers who use closed-circuit apparatus and therefore breathe oxygen 100%, do not suffer an important oxidative hyperoxia-induced stress, probably due an adaptive process after hyperoxia. The age and good physical form of the subjects studied could probably enhance the adaptive process to hyperoxia.

Effects of hyperoxia on biomarkers of oxidative stress in closed-circuit oxygen military divers

Oxygen toxicity is a problem in diving which can have fatal consequences in thewater. When divers use closed-circuit oxygen rebreathing apparatus they are takingonly oxygen 100% and this hyperoxic exposure increases the generation of reactiveoxygen species (ROS) in biological tissues. The objective of the present study is toevaluate the effects of hyperoxia on biomarkers of oxidative stress in closed-circuitoxygen military divers. Fifteen professional divers of Spanish Navy Diving Centreparticipated in a training program which consisted of one-hour immersion at sevenmetres of depth breathing oxygen 100% with closed-circuit oxygen rebreathingapparatus. The training went on two or three times per week for the first six weeksand once a week for the last six weeks. Serum total antioxidant status (TAS), levels ofglutathione peroxidase (GPx), nitrates (NO3-) and urinary concentrations of 15-isoprostaneF2t were measured. The results show that TAS decreased significantly after6 weeks (mean 1.38 versus 1.23 mmol/l), with a slight increase at the end (mean 1.31mmol/l). GPx and F2-isoprostanes were significantly lower after 6 and 12 weeks andNO3- was significantly lower after 6 weeks and remained unchanged until the end.In summary, professional divers who use closed-circuit apparatus and thereforebreathe oxygen 100%, do not suffer an important oxidative hyperoxia-inducedstress, probably due an adaptive process after hyperoxia. The age and good physicalform of the subjects studied could probably enhance the adaptive process to hyperoxia(AU)

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Pomegranate juice supplementation in chronic obstructive pulmonary disease: a 5-week randomized, double-blind, placebo-controlled trial.

OBJECTIVE: The aim of the present study is to investigate the effect of antioxidant polyphenol-rich pomegranate juice (PJ) supplementation for 5 weeks on patients with stable chronic obstructive pulmonary disease (COPD), since the oxidative stress plays a major role in the evolution and pathophysiology of COPD. DESIGN: A randomized, double-blind, placebo-controlled trial was conducted. SUBJECTS: A total of 30 patients with stable COPD were randomly distributed in two groups (15 patients each). INTERVENTIONS: Both groups consumed either 400 ml PJ daily or matched placebo (synthetic orange-flavoured drink) for 5 weeks. Trolox Equivalent Antioxidant Capacity (TEAC) of PJ, blood parameters (14 haematological and 18 serobiochemical), respiratory function variables, bioavailability of PJ polyphenols (plasma and urine) and urinary isoprostane (8-iso-PGF(2alpha)) were evaluated. RESULTS: The daily dose of PJ (containing 2.66 g polyphenols) provided 4 mmol/l TEAC. None of the polyphenols present in PJ were detected in plasma or in urine of volunteers. The most abundant PJ polyphenols, ellagitannins, were metabolized by the colonic microflora of COPD patients to yield two major metabolites in both plasma and urine (dibenzopyranone derivatives) with no TEAC. No differences were found (P > 0.05) between PJ and placebo groups for any of the parameters evaluated (serobiochemical and haematological), urinary 8-iso-PGF(2alpha), respiratory function variables and clinical symptoms of COPD patients. CONCLUSIONS: Our results suggest that PJ supplementation adds no benefit to the current standard therapy in patients with stable COPD. The high TEAC of PJ cannot be extrapolated in vivo probably due to the metabolism of its polyphenols by the colonic microflora. The understanding of the different bioavailability of dietary polyphenols is critical before claiming any antioxidant-related health benefit. SPONSORSHIP: 'Fundación Séneca' (Murcia, Spain), Project PB/18/FS/02 and Spanish CICYT, Project AGL2003-02195.

Plasmatic homocysteine concentration and its relationship with complications associated to diabetes mellitus.

BACKGROUND AND METHODS: In the search for new factors of cardiovascular risk associated to diabetes mellitus (DM), special attention has been paid in recent years to hyperhomocysteinaemia. Therefore, we have established the concentration of homocysteine (Hcy) and other biochemical parameters in the plasma of a group of 57 type 1 and 32 type 2 diabetic patients and 54 control subjects and studied whether plasmatic homocysteinaemia was related to macroangiopathy, nephropathy, retinopathy and neuropathy. Because of significant differences for plasma Hcy values between men and women in the control group, we distinguished between both groups throughout the study. RESULTS: Patients with DM had higher Hcy than control subjects (11.7+/-5.4 vs. 10.1+/-2.4 micromol/l, p<0.05). Fasting hyperhomocysteinaemia was considered as the mean of the plasma Hcy for control subjects+2 SD (14.9 micromol/l in total group, 15.6 micromol/l in males and 13.9 micromol/l in females). In the studied groups with complications, we found significant differences between normohomocysteinaemic type 1 diabetic patients and those considered hyperhomocysteinaemic by us. On the other hand, patients having type 1 DM and complications had higher plasmatic Hcy concentration than those with no complications. CONCLUSIONS: We have found a relationship between high Hcy levels and prevalence of macroangiopathy, retinopathy and nephropathy in the type 1 diabetic patients, which was not been observed in the type 2 diabetic patients of our study. As a result, we consider plasmatic Hcy a complication-risk indicator in type 1 DM, and we recommend its use together with already established biochemical parameters in the control of the evolution of the disease.

[Determination of basal GH in dementias]. / Determinación de la hormona de crecimiento basal en demencias.

We have studied the plasmatic levels of the growth hormone (GH) in a control group consisting of 72 subjects with an average age of 69.7 +/- 8.4 years and in a group of 37 patients with an average age of 69.3 +/- 9.6, of which 28 were demented (15 with degenerative dementia and 13 with non-degenerative dementia); 8 suffered from Parkinson's disease, and the rest showed signs of failing memory due to age. When comparing the plasmatic levels of GH between the patients' group and the control group we did not find significant differences between the demented and the control group, nor between the sub-groups of non-degenerative dementia or of those suffering from Parkinson's disease, when compared to the control group. However, we did find a reduction of GH that was statistically significant in the sub-group of degenerative dementia and the control group. This reduction in GH plasmatic values indicates a specific alteration in this type of process, which may be of certain use when searching for a hormonal marker for degenerative type dementia.

Soluble CD23 (sCD23) serum levels and lymphocyte subpopulations in peripheral blood in rhinitis and extrinsic and intrinsic asthma.

To determine serum levels of IgE and sCD23 and lymphocyte subpopulations, we studied 37 control subjects and 84 patients (27 with allergic rhinitis, 27 with extrinsic asthma, and 30 with intrinsic asthma). A rise in surface CD23 on B and monocyte cells and sCD23 serum levels was exhibited by patients with rhinitis and extrinsic asthma. Unexpectedly, in intrinsic asthmatic patients, high CD23 expression on monocytes and high sCD23 levels were seen that did not result in IgE production. It appears that CD23, in its soluble form, could be a good disease marker, especially in asthma. Atopic patients yielded a significantly lower proportion of CD4+ T cells than intrinsic asthmatic patients and normal persons. Otherwise, CD4+CD29+CD45RA- and CD4+CD29-CD45RA T-cell subsets were significantly decreased in all patient groups.

Determination of beta 2-microglobulin in serum by a microparticle-enhanced nephelometric immunoassay.

This fully automated nephelometric immunoassay to quantify beta 2-microglobulin in human serum measures the light-scattering signal produced by agglutination of commercially available latex microparticles (diameter 0.1 micron) coated with specific F(ab')2 against beta 2-microglobulin. The calibration curve, generated by serial dilutions of a beta 2-microglobulin standard of known concentration, is used to calculate beta 2-microglobulin concentrations in serum samples by the logit-log function and linear-regression analysis. The assay range (sample dilution 400-fold) extends from 0.3 to 40.0 mg/L. No antigen excess appears at beta 2-microglobulin concentrations up to 320 mg/L. Within-run CVs ranged from 1.0% to 3.4%, and between-days from 1.2% to 2.8%. Total imprecision (CV) was < 5%. Analytical recovery averaged 99.5% +/- 2.8%. Rheumatoid factor, complement, bilirubin (up to 340 mumol/L), and hemoglobin (up to 2.0 g/L) do not interfere. Strongly turbid lipemic samples must be cleared before analysis. Standard curve linearity was very good in samples covering the clinical useful range of concentrations. Results of the method correlated well with those of radioimmunoassay and microparticle enzyme-linked immunoassay (r = 0.979 and 0.975, respectively). The reference interval (nonparametric estimation) in apparently healthy adults (n = 303) was 0.87 (0.80-0.94) to 2.42 (2.28-2.45) mg/L; the median value was 1.54 mg/L.