Oxidative stress biomarkers in Fabry disease: is there a room for them?

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder, caused by deficient activity of the alpha-galactosidase A enzyme leading to progressive and multisystemic accumulation of globotriaosylceramide. Recent data point toward oxidative stress signalling which could play an important role in both pathophysiology and disease progression. METHODS: We have examined oxidative stress biomarkers [Advanced Oxidation Protein Products (AOPP), Ferric Reducing Antioxidant Power (FRAP), thiolic groups] in blood samples from 60 patients and 77 healthy controls. RESULTS: AOPP levels were higher in patients than in controls (p < 0.00001) and patients presented decreased levels of antioxidant defences (FRAP and thiols) with respect to controls (p < 0.00001). In a small group of eight treatment-naïve subjects with FD-related mutations, we found altered levels of oxidative stress parameters and incipient signs of organ damage despite normal lyso-Gb3 levels. CONCLUSIONS: Oxidative stress occurs in FD in both treated and naïve patients, highlighting the need of further research in oxidative stress-targeted therapies. Furthermore, we found that oxidative stress biomarkers may represent early markers of disease in treatment-naïve patients with a potential role in helping interpretation of FD-related mutations and time to treatment decision.

Dynamics of Cd, Cu and Pb added to soil through different kinds of sewage sludge.

A greenhouse experiment was set up to study the distribution of Cd, Cu and Pb in three typical soils of the Pampas Region amended with sewage sludge. A sequential extraction procedure was used to obtain four operationally defined geochemical species: exchangeable, bound to organic matter, bound to carbonates, and residual. Two kinds of sewage sludge were used: pure sewage sludge and sewage sludge containing 30% DM of its own incinerated ash, at rates equivalent to a field application of 150 t DM ha(-1). Pots were maintained at 80% of field capacity through daily irrigation with distilled water. Soil samples were obtained on days 1, 60, 270 and 360, and then air-dried and passed through a 2 mm sieve for analysis. Results showed that sludge application increased the less available forms of Cd, Cu and Pb. The inorganic forms became the most prevalent forms for Cu and Pb, whereas Cd was only found in the residual fraction. The concentrations of OM-Cu and INOR-Cu in the amended soil samples were closely correlated with soil pH, whereas the chemical behavior of Cd and Pb did not depend on soil physico-chemical characteristics.

Gliclazide protects human islet beta-cells from apoptosis induced by intermittent high glucose.

BACKGROUND: Decreased beta-cell mass, mainly due to apoptosis, is crucial for the development and progression of type 2 diabetes. Chronic exposure to high glucose levels is a probable underlying mechanism, whereas the role of oral anti-diabetic agents (sulphonylureas in particular) is still unsettled. METHODS: To directly investigate more on such issues, we prepared isolated human islets, which were then cultured for 5 days in continuous normal glucose concentration (NG, 5.5 mmol/L) or normal and high (HG, 16.7 mmol/L) glucose levels (alternating every 24 h), with or without the addition of therapeutical concentration (10 micromol L) of gliclazide or glibenclamide. RESULTS: Intermittent high glucose caused a significant decrease of glucose-stimulated insulin secretion, which was not further affected by either sulphonylurea. Apoptosis, as assessed by electron microscopy, was also significantly increased by alternating high glucose exposure, which was accompanied by altered mitochondria morphology and density volume, and increased concentrations of nitrotyrosine, a marker of oxidative stress. Gliclazide, but not glibenclamide, was able to significantly reduce high glucose induced apoptosis, mitochondrial alterations, and nitrotyrosine concentration increase. CONCLUSION: Therefore, gliclazide protected human beta-cells from apoptosis induced by intermittent high glucose, and this effect was likely to be due, at least in part, to the anti-oxidant properties of the molecule.

An alternative and simple method to consistently prepare viable isolated human islets for clinical transplantation.

We describe a method to consistently prepare human islets for transplantation. By combining a simple collagenase digestion method and a density gradient purification system, we were able to obtain successful isolations (>/=200,000 islet equivalents, >/=50% purity) in 69% of processed glands. No reagent of animal source was used. Isolated islets were morphologically well maintained and functionally competent, with sterility confirmed in 97% of cases. Two patients were transplanted with islets prepared by this method; graft function was demonstrated for a few months. Improved simplicity and consistency, together with adequate quality of the preparations, are the main features of this isolation method.

High-molecular-weight hydroxypropylmethylcellulose taken with or between meals is hypocholesterolemic in adult men.

Hydroxypropylmethylcellulose (HPMC) is a food gum that shares certain characteristics, such as high viscosity, with soluble fibers. In this trial, the safety and cholesterol-lowering efficacy of HPMC consumed with and between meals was evaluated in free-living male volunteers with mild-to-moderate hypercholesterolemia. After a 14-d baseline period, men (n = 51) with LDL cholesterol between 3.36 and 4.91 mmol/L and triglycerides <3.95 mmol/L were randomly assigned to consume 5.0 g/d HPMC in 240 mL of orange drink, taken either with or between meals, for a 2-wk treatment period. In the Between Meals group, total cholesterol was reduced by 8.0% vs. baseline in wk 1 of treatment (P < 0.05) and 5.1% in wk 2 (P < 0.01). LDL cholesterol concentrations fell by 12.0 and 7.7% (P < 0.01). In the With Meals group, reductions were 9.5 and 8.3% for total cholesterol, and 12.5 and 12.8% for LDL cholesterol (wk 1 and 2, respectively, P < 0.01). In both groups, HDL cholesterol decreased by approximately 5% during wk 1 of treatment (P < 0.01), but the wk 2 concentrations were not significantly different from baseline. There were no significant differences between groups in lipid responses, although there was a trend for a smaller LDL cholesterol-lowering effect during wk 2 of treatment in the Between Meals group (P < 0.06). Gastrointestinal-related adverse experiences (mostly mild) were twice as common among participants who ingested HPMC with meals (P < 0.05). These results suggest that HPMC has a lipid-lowering effect, which may be more consistent when taken with meals.

Long-term effects of consuming foods containing psyllium seed husk on serum lipids in subjects with hypercholesterolemia.

The effects of consuming foods containing 0 (control), 3.4, 6.8, or 10.2 g psyllium seed husk (PSH)/d for 24 wk on the serum lipid profile were assessed in this randomized, double-blind controlled study. Men and women (n = 286) with LDL-cholesterol concentrations between 3.36 and 5.68 mmol/L (130 and 220 mg/dL) were randomly assigned to one of four treatment groups after following a low-fat diet for > or = 8 wk. At week 24, LDL cholesterol was 3% above baseline in the control group. In the group consuming 10.2 g PSH/d, LDL cholesterol remained below baseline during treatment, with a value 5.3% below that of the control group at week 24 (P < 0.05 compared with the control group). No significant differences were observed in HDL cholesterol or triacylglycerol. Although modest, the effect of 10.2 g PSH/d on LDL cholesterol (relative to the control) persisted throughout the 24-wk treatment period, indicating potential for long-term benefit.

Olestra dose response on fat-soluble and water-soluble nutrients in humans.

Ninety normal healthy adults were given 0, 8, 20 or 32 g/d olestra for 8 wk as part of a diet that provided 1 +/- 0.2 of the recommended dietary allowance (RDA) of vitamins A, D, E and K, folate zinc, calcium and iron. In addition, a 20 microg/d supplement of vitamin D was supplied. The diet provided 15% of energy from protein, 35% from fat and 55% from carbohydrate. The purpose of the study was to determine the dose response of olestra on vitamins D, E and K, carotenoids, vitamin B12, folate and zinc. Circulating concentrations of retinol, carotenoids, tocopherols, 25-hydroxy- and 1,25-dihydroxyvitamin D metabolites, phylloquinone, des-gamma-carboxyprothrombin, prothrombin, folate and hematological parameters were measured biweekly, as were urine concentrations of zinc and gamma-carboxyglutamic acid (Gla). Clinical chemistry, urinalysis and vitamin B12 absorption were measured at wk 0 and 8. Olestra reduced serum concentrations of carotenoids, alpha-tocopherol, 25-hydroxyergocalciferol and phylloquinone in a dose-responsive manner. Olestra did not affect Gla excretion, plasma des-gamma-carboxyprothrombin or prothrombin concentrations, prothrombin time, vitamin B12 absorption, overall vitamin D status or the status of folate or zinc. Laboratory evaluations showed no health-related effects of olestra. Subjects in all groups reported common gastrointestinal symptoms such as loose stools, fecal urgency and flatulence, which were transient and generally mild to moderate in severity. These symptoms did not affect protocol compliance or the ability to measure the potential for olestra to affect nutrient availability.

Effects of docosahexaenoic acid on serum lipoproteins in patients with combined hyperlipidemia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: The objective of this study was to evaluate the effects of daily dietary supplementation with 1.25 g or 2.5 g of docosahexaenoic (DHA), in the absence of eicosapentaenoic acid (EPA), on serum lipids and lipoproteins in persons with combined hyperlipidemia (CHL) [serum low-density lipoprotein cholesterol (LDL-C) 130 to 220 mg/dL and triglycerides 150 to 400 mg/dL]. METHODS: After a 6-week dietary stabilization period, subjects entered a 4-week single-blind placebo (vegetable oil) run-in phase. Those with adequate compliance during the the run-in were randomized into one of three parallel groups (placebo, 1.25, or 2.5 g/day DHA) for 6 weeks of treatment. Supplements were administered in a triglyceride form contained in gelatin capsules. Primary outcome measurements were plasma phospholipid DHA content, serum triglycerides, high-density lipoprotein cholesterol (HDL-C). LDL-C and non-HDL-C. RESULTS: The DHA content of plasma phospholipids increased dramatically (2 to 3 fold) in a dose-dependent manner. Significant (p < 0.05) changes were observed in serum triglycerides (17 to 21% reduction) and HDL-C (6% increase) which were of similar magnitude in both DHA groups. Non-HDL-C [+1.6 (NS) and +5.7% (p < 0.04)] and LDL-C [+9.3% (NS) and +13.6% (p < 0.001)] increased in the DHA treatment groups. All lipid effects reached an apparent steady state within the first 3 weeks of treatment. CONCLUSION: Dietary DHA, in the absence of EPA, can affect lipoprotein cholesterol and triglyceride levels in patients with combined hyperlipidemia. The desirable triglyceride and HDL-C changes were present at a dose which did not significantly increased non-HDL-C or LDL-C. These preliminary findings suggest that dietary supplementation with 1.25 g DHA/day, provided in a triglyceride form, may be an effective tool to aid in the management of hypertriglyceridemia.

High-dose oral metoclopramide. An effective antiemetic agent.

Seventy-six patients receiving cisplatin and noncisplatin-containing cancer chemotherapy were treated with an outpatient phase II metoclopramide regimen. The program consisted of an outpatient intravenous loading dose of metoclopramide before chemotherapy, followed by oral metoclopramide at 1, 3, 5, and 8 hours after chemotherapy. Three oral dose levels were evaluated. Treatment with 2 mg/kg/dose or 100 mg/dose resulted in no vomiting in 53% of 65 evaluable patients, and 0-2 episodes of emesis in 74%. Oral doses of 50 mg/dose were less effective, preventing emesis in 18%. This trial demonstrated the antiemetic effectiveness of high-dose oral metoclopramide in a new schedule designed for the outpatient setting. The side effects included restlessness (51% of patients), dystonic reactions (9%), and gastrointestinal complaints (41%).

Antiemetic efficacy of dexamethasone therapy in patients receiving cancer chemotherapy.

To assess the value of high-dose dexamethasone therapy in preventing the gastrointestinal (GI) side effects of chemotherapy, a randomized double-blind study was conducted in women receiving outpatient therapy for breast cancer. Single-dose dexamethasone sodium phosphate (10 mg) or placebo was administered intravenously in 57 trials in 22 women immediately before chemotherapy. Questionnaires (administered before therapy and 24 hours later) were compared for evidence of nausea, vomiting, and anorexia produced by chemotherapy. No GI intolerance to chemotherapy was noted in 24 (83%) of the 29 dexamethasone trials v 16 (57%) of the 28 placebo trials. Dexamethasone trials produced the following results: no side effects in 50% (14/29), insomnia the night after chemotherapy in 21% (6/29), an increase in energy levels in 24% (7/29), and an improvement in mood in 14% (4/29). High-dose dexamethasone therapy has useful application in alleviating the emetic effects of cancer chemotherapy.

Randomized clinical trial of tamoxifen plus sequential CMF chemotherapy versus tamoxifen alone in postmenopausal women with advanced breast cancer.

Eighty-eight postmenopausal women with metastatic breast cancer, in whom estrogen receptors (ER) were positive or unknown, were treated on a controlled trial to determine the effectiveness of tamoxifen and to assess the therapeutic advantage of sequentially adding low-dose cyclophosphamide-methotrexate-5-fluorouracil (CMF) chemotherapy in tamoxifen responders. Patients with known ER negative status were not studied. After the initial 12-week treatment with tamoxifen alone, 60% of ER positive patients achieved complete or partial response as did 35% in whom ER were unknown. Response status further improved in 18% randomized to continue tamoxifen alone vs 31% in whom CMF was added to tamoxifen. There were no statistically significant differences in time to the development of progressive disease or survival between the ER positive and ER unknown patients or between the tamoxifen and tamoxifen plus CMF groups. We conclude that inability to determine ER status should not prejudice against the use of tamoxifen in postmenopausal patients with advanced breast cancer. No benefit has been demonstrated from the addition of CMF chemotherapy in tamoxifen responders.

Tamoxifen plus sequential CMF chemotherapy versus tamoxifen alone in postmenopausal patients with advanced breast cancer: a randomized trial.

Eighty-nine postmenopausal women with metastatic breast cancer, in whom estrogen receptors (ER) were positive or unknown, were treated on a controlled trial to determine the effectiveness of tamoxifen and to assess the therapeutic advantage of sequentially adding low-dose cyclophosphamide-methotrexate-5-fluorouracil (CMF) chemotherapy in tamoxifen responders. Patients with known ER negative status were not studied. After the initial 12 week treatment with tamoxifen alone, 59% of ER positive patients achieved complete or partial response as did 35% in whom ER were unknown. Response status further improved in 18% randomized to continue tamoxifen alone vs. 28% in whom CMF was added to tamoxifen. There were no statistically significant differences in time to the development of progressive disease or survival between the ER positive and ER unknown patients or between the tamoxifen and tamoxifen plus CMF groups. We conclude that inability to determine ER status should not prejudice against the use of tamoxifen in postmenopausal patients with advanced breast cancer. As yet, no benefit has been demonstrated from the addition of CMF chemotherapy in tamoxifen responders.