Maria Montana

Effects of red orange juice intake on endothelial function and inflammatory markers in adult subjects with increased cardiovascular risk

BACKGROUND Oxidative and inflammatory stresses are involved in the pathogenesis of atherosclerosis. The consumption of fruit and vegetables is associated with improved health and reduced cardiovascular risk. Red oranges have a high content of antioxidant and antiinflammatory substances, but there is a paucity of data concerning their effects on cardiovascular biomarkers in subjects with increased cardiovascular risk. OBJECTIVE We investigated the effect of red orange juice intake on endothelial function, oxidative stress, and markers of inflammation in subjects with increased cardiovascular risk. DESIGN Nineteen nondiabetic subjects with increased cardiovascular risk (aged 27-56 y) were included in a randomized, placebo-controlled, single-blind crossover study and compared with 12 healthy, nonobese control subjects. In 2 periods of 7 d each with a 3-d interval, each participant alternatively received 500 mL red orange juice/d and 500 mL placebo/d in a random sequence. All measurements were performed in the morning after overnight fasting. RESULTS Endothelial function, which was measured as flow-mediated dilation, significantly improved and was normalized (5.7% compared with 7.9%; P < 0.005) after 1 wk of red orange juice consumption. Similarly, concentrations of high-sensitivity C-reactive protein, IL-6, and TNF-α significantly decreased (P < 0.001). Red orange juice had no significant effect on nitric oxide plasma concentrations. CONCLUSION A 7-d consumption of red orange juice ameliorates endothelial function and reduces inflammation in nondiabetic subjects with increased cardiovascular risk. This trial was registered at biomedcentral.com as ISRCTN39987296.

Oxidative Stress in Young Subjects With Acute Myocardial Infarction: Evaluation at the Initial Stage and After 12 Months

In 105 subjects (97 men and 8 women) aged <46 years (mean age 39.6 ± 5.5 years), with recent acute myocardial infarction (T1), thiobarbituric acid reactive substances and total antioxidant status were determined; NO production was evaluated by measuring the nitrite and nitrate (NOx) concentration. The patients with acute myocardial infarction were subdivided according to the main risk factors, number of risk factors, and extent of coronary lesions. The evaluation was repeated after 12 months (T2). In these subjects, thiobarbituric acid reactive substances and NOx were significantly increased and total antioxidant status was significantly decreased at T1. In single risk factor, only NO metabolites were significantly lower in acute myocardial infarction subjects who smoke than in subjects who do not. Subdividing the subjects according to the number of risk factors and number of stenosed coronary vessels, there were no significant differences between the subgroups. At T2, thiobarbituric acid reactive substances and NOx were decreased and total antioxidant status was increased, but all parameters were still altered.

Granulocyte integrins before and after activation in acute ischaemic stroke.

We examined in 19 subjects with acute ischaemic stroke (AIS) the PMN integrin pattern (CD11a, CD11b, CD11c, CD18), using indirect immunofluorescence and adopting a flow cytometer, at baseline and during activation, prolonged for 5 and 15 min, with 4-phorbol 12-myristate 13-acetate (PMA). At baseline, an increase in the expression of CD11c and CD18 and a decrease in the CD11b were evident in AIS subjects compared to normals. After activation, we found in normals a constant and significant increase of all PMN adhesive molecules, while in AIS subjects, we found an increase in CD11b and CD18, a decrease in CD11a and no variation in CD11c. While the basal upregulation of CD11c and CD18 may depend on the PMN spontaneous activation or on the increase of cytokines, the decrease of CD11b may be due to its self-consumption. After activation, the decrease in CD11a noted in AIS may be related to its cleavage or to an altered integrin phosphorylation/dephosphorylation balance.

Gelatinases and Their Tissue Inhibitors in a Group of Subjects With Metabolic Syndrome

Aim To evaluate matrix metalloproteases (MMP)-2 and MMP-9 and tissue inhibitor of metalloproteases (TIMP)-1 and TIMP-2 in a group of subjects with metabolic syndrome (MS) subdivided according to the presence or absence of diabetes mellitus. Methods We examined in 90 subjects (51 men and 39 women) with MS, defined following the International Diabetes Federation criteria, and subsequently subdivided into diabetic subjects (22 men and 11 women) and nondiabetic subjects s (29 men and 28 women), the plasma concentrations of MMP-2 and MMP-9 and of TIMP-1 and TIMP-2 using specific enzyme-linked immunosorbent assay kits. Results We found a significant increase in plasma concentrations of MMP-2, MMP-9, TIMP-1, and TIMP-2 in the whole group of MS subjects (P < 0.001) and in both subgroups of MS subjects with diabetes mellitus (P < 0.001) and without diabetes mellitus (P < 0.001) in comparison with healthy controls. We also noted higher concentrations of all the examined parameters in the MS subjects with diabetes mellitus in comparison with the MS subjects without diabetes mellitus. Matrix metalloproteases and TIMPs showed some significant correlations with body mass index and waist circumference and with metabolic parameters in the whole group of MS subjects. Conclusion An altered pattern of MMPs and their inhibitors is demonstrated in MS; the presence of diabetes mellitus strongly influences the concentration of MMP and TIMP, contributing probably to the increased cardiovascular risk of MS subjects.

Lipid peroxidation and total antioxidant status in unprofessional athletes before and after a cardiopulmonary test.

We examined lipid peroxidation, expressed as thiobarbituric acid-reactive substances (TBARS) and total antioxidant status (TAS) before and after a cardiopulmonary test, in 20 sedentary controls and in 62 unprofessional male athletes subdivided into 3 subgroups. The first included subjects who practised endurance sports (14 cyclists and 9 endurance swimmers), the second subjects who practised mixed sports (6 basket players, 6 judoists, 8 water polo players) and the third group subjects who practised power sports (3 sprint runners, 4 weightlifters, 12 sprint swimmers). In the whole group of athletes an increase in TBARS and a decrease in TAS were present at baseline. Subdividing the whole group into three subgroups we observed an increase in TBARS in all and a decrease in TAS only in the endurance and mixed athletes. After the test, TBARS showed a more significant increase in controls compared to the whole group and each subgroup of athletes, while TAS increased only in the whole group and in those who practised mixed sports. In conclusion, at baseline in athletes the oxidative status shows a different behaviour compared to controls, while after the test the antioxidant protection is more marked and it may be related to an increase of antioxidant systems.

Elastase, myeloperoxidase, nitric oxide metabolites and oxidative status in subjects with clinical stable chronic renal failure on conservative treatment

We evaluated, in a group of 41 CRF undialyzed subjects (29 men and 12 women, mean age 64.1 +/- 11.3 years), some parameters that reflect leukocyte activation (elastase, myeloperoxidase - MPO), plasma NO metabolites (NO(x)) and the oxidative status (lipid peroxidation expressed as thiobarbituric acid-reactive substances (TBARS) and total antioxidant status (TAS). Elastase was determined, on plasma separated from fasting venous blood, as elastase/alpha1-proteinase inhibitor complex. MPO was evaluated employing the Myeloperoxidase ELISA kit. The NO production was evaluated by a micromethod. The oxidation of polyunsaturated fatty acids was evaluated in plasma by detection of the thiobarbituric acid-reactive substances (TBARS). Total antioxidant status was measured by spectrophotometry. We found a significant increase of elastase, TBARS and NO(x), without any significant variation of MPO and TAS. In this group of CRF subjects, no statistical correlation was found between these examined parameters, creatinine level, creatinine clearance, leukocyte count and hemoglobin level. These findings need to be underlined if we consider that chronic renal failure is an inflammatory condition and this research furtherly supports literature data regarding the role of activated leukocytes in the development of the vascular complications. These observations explain why the examination of leukocyte count and function could become a tool to verify the clinical outcome in these patients.

Screening and study enrolment in the Randomized Evaluation of Normal vs. Augmented Level (RENAL) Replacement Therapy Trial

Background and Objectives: Aspects of trial design, screening and study efficiency can affect recruitment and the findings of the trial itself. A clear understanding of the screening and study inclusion process will assist clinicians in interpreting trial results. Design: Prospective observational data collection on all patients screened for possible inclusion in a randomized controlled trial of normal vs. augmented renal replacement therapy in critically ill patients (the RENAL Trial). Setting: 35 hospitals in Australia and New Zealand. Participants: All patients screened for the RENAL Trial. Results: We screened 4,551 patients. Of these patients, 767 were ineligible because of lack of inclusion criteria and 2,085 because of exclusion criteria. Of the remaining 1,699, 1,508 (88.7%) were enrolled. The three most common exclusion criteria which prevented recruitment of potentially eligible patients were that the patient had end-stage kidney failure and was already on chronic dialysis (484; 23.2%), the patient’s body weight was either <60 or >120 kg (456; 21.8%), and the fact that the patient had already received renal replacement therapy during the index admission. Important modifiable impediments to recruitment were inability to obtain consent in 191 cases, unavailability of research staff in 124 cases, physician objection in 89 cases, and inability to deliver the trial protocol in 78 cases. Conclusion: The RENAL Trial’s enrolment efficiency was high and compared favourably with previous large intensive care units trials and with that of trials in patients with acute renal failure. The high rate of enrolment suggests that the results can be applied with confidence to most patients with de novo acute renal failure. The loss of close to 1.5% of patients due to consent issues highlights a common problem in critical care trials. The low rate of physician objection suggests clinical equipoise.

Nitric oxide metabolites, leukocyte activation markers and oxidative status in dialyzed subjects.

Aims: Our purpose was to evaluate, in a group of 42 end-stage renal disease patients who regularly undergo hemodialysis, some indexes of leukocyte activation, nitric oxide metabolites (NOx) and other parameters that reflect the oxidative stress before and after a standard hemodialysis session. Methods: Elastase and myeloperoxidase (MPO) were determined by means of ELISA. The NO production was evaluated by a micromethod which measures the concentration of NOx. The oxidation of polyunsaturated fatty acids was evaluated in plasma by detection of thiobarbituric acid-reactive substances (TBARS). Total antioxidant status (TAS) was obtained using spectrophotometry. Results: At baseline, we observed an increase of elastase, NOx, TBARS and TAS, without any variation of MPO. After the dialysis session, we found an increase in elastase and MPO, a decrease in NOx and TAS and no variation in TBARS. No modification occurred after subdividing the patients in two subgroups. Conclusions: Our data confirm the involvement of leukocytes and oxidative stress in hemodialysis patients.

Membrane Fluidity, Membrane Lipid Pattern, and Cytosolic Ca2+ Content in Platelets from a Group of Type II Diabetic Patients with Macrovascular Complications

OBJECTIVE To evaluate platelet membrane fluidity and some platelet metabolic parameters in type II diabetic patients with macrovascular complications. RESEARCH DESIGN AND METHODS In a group of 21 type II diabetic patients with macrovascular complications, we evaluated platelet membrane fluidity [marking intact resting platelets with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH)], platelet membrane lipid pattern (cholesterol :phospholipid [C:PL] ratio and individual phospholipids), and platelet cytosolic Ca2+ content (marking intact resting platelets with the fluorescent probe Fura 2AM). RESULTS Platelet membrane fluidity is decreased in type II diabetic patients with macrovascular complications compared with normal subjects (P < 0.001). Platelet membrane C:PL ratio and cytosolic Ca2+ content do not discriminate normal subjects from diabetic patients, and for individual phospholipids, only phosphatidylethanol-amine is decreased in diabetic patients compared with control subjects (P = 0.051). In normal subjects, the polarization degree of TMA-DPH is related to phosphatidylserine (P < 0.05) and phosphatidylcholine (P < 0.05), and in diabetic patients the polarization degree of TMA-DPH is related to C:PL ratio (P < 0.05) and sphyngomyelin (P < 0.05). CONCLUSIONS In type II diabetic patients with macrovascular complications, we observed an abnormality of platelet membrane fluidity, which may contribute to platelet functional alteration present in this clinical condition.

Platelet membrane fluidity and platelet membrane lipid pattern in essential hypertension

In a group of subjects with essential hypertension platelets were studied in resting conditions: platelet membrane fluidity was measured with the fluorescent probe 1.4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH), platelet membrane cholesterol/phospholipid ratio was evaluated separating the membrane lipids with column chromatography, and platelet membrane individual phospholipids were determined using two-dimensional thin-layer chromatography. From the obtained results, it is evident that platelet membrane fluidity does not differentiate normals from hypertensives; platelet membrane cholesterol/phospholipid ratio is increased in hypertensives, while of the platelet membrane individual phospholipids, only the phosphatidylcholine is increased. In normals and hypertensives, no relation is evident between platelet membrane fluidity, platelet membrane lipid pattern, and systolic and diastolic blood pressure values.