Moderate oral supplementation with docosahexaenoic acid improves platelet function and oxidative stress in type 2 diabetic patients.

Platelets from patients with type 2 diabetes are characterised by hyperactivation and high level of oxidative stress. Docosahexaenoic acid (DHA) may have beneficial effects on platelet reactivity and redox status. We investigated whether moderate DHA supplementation, given as a triglyceride form, may correct platelet dysfunction and redox imbalance in patients with type 2 diabetes. We conducted a randomised, double-blind, placebo-controlled, two-period crossover trial (n=11 post-menopausal women with type 2 diabetes) to test the effects of 400 mg/day of DHA intake for two weeks on platelet aggregation, markers of arachidonic acid metabolism, lipid peroxidation status, and lipid composition. Each two week-period was separated from the other by a six-week washout. Daily moderate dose DHA supplementation resulted in reduced platelet aggregation induced by collagen (-46.5 %, p< 0.001), and decreased platelet thromboxane B2 (-35 %, p< 0.001), urinary 11-dehydro-thromboxane B2 (-13.2 %, p< 0.001) and F2-isoprostane levels (-19.6 %, p< 0.001) associated with a significant increase of plasma and platelet vitamin E concentrations (+20 % and +11.8 %, respectively, p< 0.001). The proportions of DHA increased both in plasma lipids and in platelet phospholipids. After placebo treatment, there was no effect on any parameters tested. Our findings support a significant beneficial effect of low intake of DHA on platelet function and a favourable role in reducing oxidative stress associated with diabetes.

Dose-effect and metabolism of docosahexaenoic acid: pathophysiological relevance in blood platelets.

Docosahexaenoic acid (DHA) is known as a major nutrient from marine origin. Considering its beneficial effect in vascular risk prevention, the effect of DHA on blood components, especially platelets, will be reviewed here. Investigating the dose-effect of DHA in humans shows that daily intake lower than one gram/day brings several benefits, such as inhibition of platelet aggregation, resistance of monocytes against apoptosis, and reinforced antioxidant status in platelets and low-density lipoproteins. However, higher daily intake may be less efficient on those parameters, especially by losing the antioxidant effect. On the other hand, a focus on the inhibition of platelet aggregation by lipoxygenase end-products of DHA is made. The easy conversion of DHA by lipoxygenases and the formation of a double lipoxygenation product named protectin DX, reveal an original way for DHA to contribute in platelet inhibition through both the cyclooxygenase inhibition and the antagonism of thromboxane A2 action.

The influence of low intake of n-3 fatty acids on platelets in elderly people.

A total of ten healthy elderly subjects ingested one capsule of 600 mg (corresponding to 150 mg docosahexaenoic acid and 30 mg eicosapentaenoic acid) RO-PUFA triglycerides per day and ten others ingested one capsule of 600 mg sunflower oil as a placebo for 42 days. In the n-3 polyunsaturated fatty acids (PUFA) group, a significant decrease of systolic blood pressure was observed, as well as a trend towards a decrease in both platelet activation and basal formation of thromboxane B(2). Also, a slight but significant increase of docosahexaenoic acid was observed in the phosphatidylethanolamine fraction as well as a significant increase of vitamin E level after the n-3 PUFA intake. Moreover, the basal production of malondialdehyde significantly decreased. No modification was observed for all these parameters in the placebo group. We conclude that a small intake of n-3 PUFA decreased the oxidative stress in platelets of elderly people and could be beneficial in subjects with atherothrombotic tendencies by lowering the cell peroxide tone.

The influence of antioxidant nutrients on platelet function in healthy volunteers.

There is mounting evidence that antioxidants may help to prevent coronary heart disease and modulate some thrombotic events such a platelet adhesion. However, the effects of antioxidant supplementation on platelet function in vivo are controversial. A double-blind, randomised, placebo-controlled study was performed on 40 healthy volunteers (20-50 years) supplemented daily with vitamin E (300 mg), vitamin C (250 mg) or beta-carotene (15 mg) for 8 weeks. Platelet function was assessed by platelet aggregation induced by ADP, arachidonic acid or collagen, platelet responsiveness to the inhibitor PGE1, beta-thromboglobulin release and ATP secretion. Supplementation with vitamin E resulted in a significant increase in platelet alpha-tocopherol level (+68%) reflecting closely the increase in plasma alpha-tocopherol level (+69%). Platelet function was significantly decreased by vitamin E as revealed by the decreased platelet aggregation in response to ADP and arachidonic acid, the increased sensitivity to inhibition by PGE1, the decreased plasma beta-thromboglobulin concentration and the decreased ATP secretion. Supplementation with vitamin C did not affect platelet function significantly although a trend towards a decreased platelet aggregability and an increased sensitivity to the inhibitor PGE1 were observed. No significant changes in platelet function occurred after supplementation with beta-carotene. In conclusion, supplementation of healthy volunteers with vitamin E decreased platelet function whereas supplementation with vitamin C or beta-carotene had no significant effects.

Levels of antioxidant nutrients in plasma and low density lipoproteins: a human volunteer supplementation study.

A human supplementation study was undertaken in order to investigate the correlation between the intake of individual daily dosages of vitamin E (300 mg), vitamin C (250 mg), or beta-carotene (15 mg) of eight week duration and their uptake in vivo in plasma and LDL. The effects of a combined supplement of vitamin E, vitamin C and beta-carotene (Redoxon protector-75 mg, 150 mg, 15 mg respectively) were also investigated. The results show that on supplementation with the individual antioxidants the increases in plasma alpha-tocopherol:cholesterol levels lie in the 1.5-2 fold range and the beta-carotene:cholesterol ratios give a mean 3.5 fold enhancement. The combined supplement containing the same level of beta-carotene as the single dosage achieved comparative levels of uptake in plasma. The level of plasma vitamin C appears to be maximal at about 100 microM regardless of the pre-supplementation level.

[Effects of traditional cooking on antinutritional factors of the black beans (Phaseolus vulgaris) of Costa Rica]. / Efectos de la cocción tradicional sobre los factores antinutricionales de los frijoles negros (Phaseolus vulgaris) de Costa Rica.

Trypsin inhibitors, alfa amylase inhibitors and hemagglutinins were determined in black beans (P. vulgaris) produced in Costa Rica. The effect of the traditional cooking on such antinutritional factors was also studied. The antinutritional factors were analyzed spectrophotometrically in the raw beans, as well as after several cooking periods of time. The results showed that alfa-amylase inhibitors were the most thermoresistant. After 30 min of cooking time there was a 33% of activity left from the initial activity of the raw beans. Approximately 80% of the antitryptic activity was destroyed at 9 min of cooking time. After 10 min of cooking time, only 1% of hemagglutinin activity was present.

Different hemodynamic responses between acute and chronic infusion of iloprost (prostacyclin-stable analogue) in severe pulmonary hypertension.

We report the hemodynamic and clinical effects of acute and chronic administration of iloprost in two patients with severe pulmonary hypertension caused by toxic oil syndrome. We tested the acute effect of progressive increments of iloprost, followed by long-term infusion of the drug during 14 days. The acute response produced an increase in cardiac output and moderate reduction in pulmonary vascular resistance, with no change in pulmonary artery pressure. Nevertheless, a maintained reduction in pulmonary artery pressure and resistance, as well as clinical improvement, was observed after chronic infusion. We conclude that (1) the acute effect of iloprost does not necessarily predict long-term hemodynamic response, and (2) iloprost given in long-term infusion seems to have been an efficacious and safe drug in our two patients, and it opens a new line of treatment.

Clinical and pathologic manifestations of pulmonary vascular disease in the toxic oil syndrome.

The toxic oil syndrome in Spain affected greater than 20,000 people. In the initial stages, it was characterized by a respiratory distress syndrome with myalgias and eosinophilia. Pulmonary hypertension developed in 20% of the patients and in many, it has spontaneously regressed. Nevertheless, in a small subgroup, it has progressed to a malignant course of cor pulmonale, leading rapidly to death. Clinical and pathologic features of 40 patients with severe pulmonary hypertension due to the toxic oil syndrome are presented (32 female and 8 male patients; mean age 26 +/- 13 years). The study began in June 1981, which was near the onset of the toxic oil epidemic, and ended in December 1987, greater than 6 years later. The pulmonary hypertension is clinically and pathologically indistinguishable from primary pulmonary hypertension. Direct endothelial injury by the toxic agent is proposed as the initial trigger of this type of pulmonary hypertension, but an interaction between the toxic agent and specific individual susceptibility is probably required in its pathogenesis.

Dynamic pulmonary arterial hypertension: a new form of pulmonary hypertension in patients with impaired pulmonary diffusing capacity due to toxic oil syndrome.

The authors studied the pulmonary haemodynamic response to exercise in eleven patients with toxic oil syndrome (TOS) (mean age 38.3 +/- 15.7 years; 10 women, 1 man) and abnormal pulmonary diffusing capacity (39.1 +/- 10.3% of predicted value) without clinical evidence of pulmonary hypertension. Eight patients had normal pulmonary pressure at rest (mean PAP less than 25 mmHg) and three showed mild pulmonary hypertension. After exercise the mean PAP rose to 35.3 +/- 11.5 mmHg from a basal value of 20.72 +/- 3.8 mmHg (p less than 0.01). Only four patients did not develop pulmonary hypertension during exercise. Pulmonary artery oxygen saturation decreased from 72.9 +/- 1.9% at rest to 52.3 +/- 10.1% during exercise (p less than 0.01). In conclusion, in this subset of TOS patients, an early diagnosis of their subclinical pulmonary hypertension can be made on the basis of the presence of dyspnoea and abnormal pulmonary diffusing capacity for carbon monoxide and can be then confirmed with the exercise haemodynamic test.

Severe pulmonary arterial hypertension due to toxic oil syndrome: a new cause of plexogenic arteriopathy.

Ten patients with severe pulmonary hypertension due to Toxic Oil Syndrome (TOS) (3 men, 7 women; mean age 27.9 +/- 11.23 yrs.) are presented. The pulmonary vessels were examined with a micromorphometric technique. All patients had intimal fibrosis of the arteries and veins. Seven also had a thrombus in different stages. All arteries were shown to have medial hypertrophy. Plexiform lexions were found in eight cases. It is concluded that TOS can produce severe pulmonary hypertension histologically undistinguishable from the primary form. TOS can be added to the list of diseases causing plexogenic arteriopathy.

Acute effect of intrapulmonary enalaprilat in ten patients with severe pulmonary hypertension due to toxic oil syndrome.

Ten patients with severe pulmonary hypertension due to Toxic Oil Syndrome underwent cardiac catheterization to analyse the acute effect of intrapulmonary injection of 1.25 mg of enalaprilat. Haemodynamic parameters were obtained at basal state, 15, 30, 45 and 60 minutes after administration of the drug. Enalaprillat did not produce any statistically significant changes in pulmonary pressures and resistances or cardiac output. This lack of response is unknown but may be related to the presence of endothelial damage and fixed pulmonary vascular lesions observed at autopsy in three patients.

[Cystic duplication of the rectum]. / Duplication kystique du rectum.

Cyst or intestinal duplications can arise anywhere along the gut, however those located in the rectum are very rare and only a few dozen cases have been reported. The reason that induced us to report this patient is double: first to present a new case of rectal duplication diagnosed at 45 days old that had a normal barium enema previously, second to confirm once more that the muscular complex of the rectum can be cut in the posterior middle line without any damage to the rectal continence function, as Peña's surgical approach for anorectal atresias. The case reported correspond to a newborn weighing 2,850 grs who had exomphalos of 5 cm. Wide with an integral sac and was operated by primary closure. When he was 10 days old, and because he had some intestinal disturbances compatible with malrotation, a barium enema was done that was normal. He was discharged and returned 30 days later because of striped feces and constipation. Rectal examination showed a retrorectal tumor located at left posterolateral space. Ultrasound showed a cystic mass and barium enema displayed a narrowed rectum channel. First we did a Wangesteen colostomy. Ten days later, by a sagittal posterior approach cutting the Levator and Muscular Complex of the rectum in the middle line and without opening the lumen, a tumor like a nut, sharing its muscular coat with the rectum, was excised. The Muscular Complex and the Levator were repaired with the aid of the electrostimulator. After the 7 day postoperation we made some rectal dilatations and closure of colostomy at 21 day.(ABSTRACT TRUNCATED AT 250 WORDS)