Biomedical subjects

R Lombardini

Publications and source records attributed to R Lombardini.

At least 19 recordsLinked to original sources

PubMed2005

Prognostic impact of low-shear whole blood viscosity in hypertensive men.

BACKGROUND: The role of blood viscosity as a marker for discriminating cardiovascular risk in essential hypertension remains uncertain. The aim of this study was to assess whether whole blood viscosity (WBV) could be useful in assessing cardiovascular risk in men with a first diagnosis of hypertension. DESIGN: A total of 331 middle-aged men with newly diagnosed essential hypertension (age at entry 40-64 years, average blood pressure 151/95 mmHg) underwent low-shear-rate (0.94 s(-1)) and high-shear-rate (94.5 s(-1)) WBV determination and were then followed for a mean of 4.8 +/- 3 years (range 0-12 years). RESULTS: Cardiovascular event rates in the bottom, middle and top tertiles of the distribution of low-shear WBV were 1.10, 2.13 and 4.43 per 100 patient-years, respectively (log-rank test, P < 0.001). After taking into account several established cardiovascular risk factors in a Cox survival analysis, a raised low-shear WBV conferred an increased risk for cardiovascular events (top vs. bottom tertile hazard ratio = 3.42, 95% confidence interval = 1.4-8.4, P = 0.006; middle vs. bottom tertile hazard ratio = 2.25, 95% confidence interval = 0.9-5.6, P = 0.09). The independent association between high-shear-rate WBV and cardiovascular events bordered statistical significance (P = 0.07). Inclusion in the survival model of low-shear-rate resulted in a significantly greater chi(2) improvement (P < 0.05) than inclusion of high-shear-rate WBV. CONCLUSIONS: In hypertensive men, an increased WBV at low shear rate is a predictor of cardiovascular events independently from the effect of several traditional risk factors. Low-shear WBV is a better discriminator of cardiovascular risk than high-shear WBV.

Adult↗

PubMed2003

Effects of fenofibrate on endothelial function and cell adhesion molecules during post-prandial lipemia in hypertriglyceridemia.

BACKGROUND: Fasting and post-prandial hypertriglyceridemia have been associated with endothelial dysfunction. OBJECTIVE: To investigate the effects of a 3-month treatment with fenofibrate (200 mg daily) on endothelial reactivity and inflammatory state in hypertriglyceridemic patients at fast and after an oral fat load. METHODS: Brachial flow-mediated vasodilation (FMV) and the circulating levels of intercellular adhesion molecule (ICAM) and vascular cellular adhesion molecule (VCAM) were determined in 10 hypertriglyceridemic patients. RESULTS: Before treatment, post-prandial phase was characterized by an increase in triglycerides (3.7 +/- 1 mmol/L at baseline vs. 4.2 +/- 1, 6.5 +/- 1, 6.6 +/- 2, and 5.3 +/- 2 mmol/L after 2, 4, 6, and 8 h), a decrease in FMV (4.3 +/- 2% at baseline vs. 2.8 +/- 1, 2.2 +/- 1, and 1.3 +/- 1% after 2, 4, and 6 h), and an increase in ICAM and VCAM. After fenofibrate there was a significant reduction in fasting triglycerides (3.7 +/- 1.3 vs. 2.1 +/- 0.8 mmol/L), ICAM (480 +/- 113 vs. 269 +/- 65 ng/mL) and VCAM (1821 +/- 570 vs. 1104 +/- 376 ng/mL), and an increase in FMV (4.3 +/- 2 vs. 7.1 +/- 2%). Post-prandially triglycerides increased (2.1 +/- 1 at baseline vs. 2.4 +/- 2 and 3.6 +/- 1 mmol/L after 4 and 6 h), FMV decreased (7.1 +/- 2 at baseline vs. 5.8 +/- 2, 5.5 +/- 2, 5.9 +/- 2, 6.4 +/- 2% after 2, 4, 6, and 8 h), and there was an increase of ICAM and VCAM. Before therapy post-prandial changes in FMV had an inverse correlation with the changes in triglycerides (r = -0.34; P < 0.05) and ICAM (r = -0.66; P < 0.001). CONCLUSIONS: The transient endothelial dysfunction observed in hypertriglyceridemic subjects during post-prandial lipemia is mediated by post-prandial triglyceride increase and by the activation of inflammatory response. The anti-inflammatory activity of fenofibrate may represent an additional mechanism of its favorable action on the endothelial function during fasting and the post-prandial phase.

Adult↗

PubMed2002

Blood rheology in men with essential hypertension and capillary rarefaction.

The pathophysiological significance of hyperviscosity and capillary rarefaction in untreated essential hypertension is unknown. Fifty untreated hypertensive men with capillary rarefaction (intravital capillaroscopy) and 20 age- and sex-matched normotensive controls underwent full haemorheological profiling (blood viscosity at high and low shear, haematocrit, platelet and leukocyte counts, fibrinogen and total protein concentrations, P-selectin levels, erythrocyte and leukocyte filterability rates and erythrocyte deformability and aggregation indexes). Subjects with skin capillary density below the group median had younger age, higher diastolic pressure, higher blood viscosity at low shear, higher P-selectin levels, higher erythrocyte and leukocyte filterability rates, and higher erythrocyte aggregation indexes (all P < 0.01). In contrast, patients with greater skin capillary density had a greater plasma viscosity (P < 0.05). The conclusions were that in untreated hypertensive men, capillary rarefaction and hyperviscosity are associated to an increased diastolic blood pressure and to an adverse haemorheological profile.

Adult↗

PubMed2002

A human model of platelet-leucocyte adhesive interactions during controlled ischaemia in patients with peripheral vascular disease.

AIMS: In humans, little is known about the effects of platelet-leucocyte interactions on blood viscosity and microvascular perfusion. This study tested the hypotheses that (1) activation and interactions between platelets and leucocytes may have an impact on microvascular blood viscosity and perfusion in patients with stage II peripheral arterial occlusive disease, and (2) a powerful antiplatelet drug such as Clopidogrel might help to improve microvascular perfusion by reducing platelet-leucocyte activation and blood viscosity. METHODS: Plasma concentrations of certain markers of leucocyte and platelet activation, in addition to low and high shear rate blood viscosity, were measured before and after a repeated exercise treadmill test. Functional parameters including maximum walking time, transcutaneous oxygen pressure, and half recovery time were also measured. RESULTS: Blocking platelet activation only with a single dose of Clopidogrel (300 mg) did not improve microvascular blood viscosity and perfusion after repeated exercise, but a significant improvement in microvascular perfusion during controlled ischaemia and a lack of post exercise increase in low shear rate blood viscosity was achieved when both platelet and leucocyte activation were suppressed by a relatively longer treatment with Clopidogrel (four days). CONCLUSIONS: Clopidogrel, by inhibiting platelet activation and aggregation, might also block the vicious cycle of leucocyte-platelet activation, thus improving the functioning of the microcirculation.

Adult↗

PubMed2001

Clopidogrel: hemorheological effects in subjects with subclinical atherosclerosis.

The usefulness of Clopidogrel as inhibitor of platelet aggregation has been demonstrated, but its effect on hemoreological parameters, such as whole blood viscosity at low and high shear rate, red cell aggregation and deformability indexes, filterability rate and and deformability of red blood cells has not been studied. This study revealed that, in subjects with impaired blood rheology and ultrasound evidence of atherosclerosis, 3-weeks treatment with clopidogrel (75 mg daily) improved blood viscosity at high shear rate and other hemorheological parameters, including red cell filterability rates and dynamic red cell deformability index (p<0.01 for all), without any unwanted side effect. Blood viscosity at low shear rate and red cell aggregation index improved after only 1-week treatment, and the reductions were mantained after two and three weeks (p<0.01). These results indicate that, similarly to another thienopyridine such as ticlopidine, Clopidogrel may have a positive influence on several hemorheological parameters, thus exerting its protection not only through inhibition of platelet function, but also through changes in the hemorheological profile.

Adult↗

PubMed2000

Flow-mediated vasoactivity and circulating adhesion molecules in hypertriglyceridemia: association with small, dense LDL cholesterol particles.

BACKGROUND: Endothelial dysfunction is considered one of the earliest events in the process of atherosclerosis, and an impaired vasodilatory response has been reported in patients with dyslipidemias. However, the independent association between hypertriglyceridemia and endothelial dysfunction is controversial, and the relation between endothelium-dependent vasodilation and circulating cell adhesion molecules as markers of endothelial dysfunction has not been fully determined. METHODS: Brachial artery flow mediated vasodilation (FMV) and the soluble forms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) were determined after overnight fasting in 16 men with hypertriglyceridemia (age 33 +/- 6 years) and in 16 age-matched healthy men with normal triglycerides and cholesterol. Subjects who smoked and those with known cardiovascular disease, diabetes, hypertension, recent or active infections, or any other disease that could affect leukocyte activation were excluded from the study. RESULTS: Compared with normal subjects, subjects with hypertriglyceridemia showed a higher level of sVCAM-1 and sICAM-1 (both P <.001), a reduced FMV (P <.01), and a smaller LDL particle size (P <.05). FMV had a significant inverse correlation with sVCAM-1 (r = -0.61, P <.001) and sICAM-1 (r = -0.38, P <.03). LDL particle size had a strong, direct association with FMV (r = 0.75, P <.001) and an inverse association with adhesion molecules. By multiple regression analysis, triglycerides (P <.001) and small LDL particle size (P <.002) predicted a reduced FMV. CONCLUSIONS: Serum level of cell adhesion molecules is increased and FMV is impaired in young healthy men with hypertriglyceridemia compared with age-matched men with normal lipid levels. Small, dense LDL particles may play a role in determining endothelial dysfunction in these subjects.

Adult↗

PubMed1999

Circulating leucocyte adhesion molecules in chronic venous insufficiency.

BACKGROUND: Enzyme-linked immunosorbent assay (ELISA) techniques have detected the existence of circulating forms of intercellular adhesion molecule-1 (ICAM-1), vascular endothelial adhesion molecule-1 (VCAM-1) and E-selectin, all of which mediate leucocyte-endothelial adhesion. This study determined whether circulating cell adhesion molecules were increased in patients with chronic venous insufficiency (CVI) which causes venous stasis. PATIENTS AND METHODS: Before and after walking and upon recovery blood samples were drawn from the saphenous vein in 20 CVI patients: 10 with varicose veins (group 1), 10 with deep venous insufficiency (group 2). 10 healthy controls were enrolled. The total leucocyte count and the soluble levels of ICAM-1, VCAM-1 and E-selectin were determined. RESULTS: After walking, the total leucocyte count decreased significantly (p < 0.01) only in group 2 and sICAM-1 and sVCAM-1 increased significantly (p < 0.01). Upon recovery, these significant differences remained in group 2. No significant modification was observed at any stage of the study in group 1 or in the control group. CONCLUSIONS: These results suggest persistently high levels of circulating adhesion molecules may contribute to worsen microvascular perfusion, which leads to the onset of trophic damage in CVI.

Adult↗

PubMed1999

Hyperhomocyst(e)inemia is associated with carotid atherosclerosis.

The atherogenicity of homocyst(e)ine--H(e) --emerged from many studies showing an association between moderately elevated levels and vascular occlusive disease. The aim of this study was to evaluate whether high homocyst(e)ine levels were associated with carotid atherosclerosis. Carotid atherosclerosis was defined as an intimal media thickness of internal and carotid bifurcation of at least 2 mm on the near and far walls as determined by B-mode ultrasonography. The study population included 91 patients: group 1 (61% males, mean age 64+/-10 years, 57% with history of hypertension) with ultrasound evidence of carotid atherosclerosis and 100 with normal carotid walls--group 2 (36% males, mean age 52+/-15 years, 27% with history of hypertension). Homocyst(e)ine levels (mol/L) were determined by high-performance liquid chromatography with a fluorescent detector. Body mass index, dyslipidemia, smoking, diabetes, serum creatinine, plasma folic acid and vitamin B12 were not significantly different in the two groups. Homocyst(e)ine levels (micromol/L) were significantly higher in patients with carotid ather osclerosis than in those with normal arteries (11.7+/-6.5 micromol/L, 95% CI 10.4-13.1 vs 8.07+/-4.4 micromol/L, 95% CI 7.2-8.9, p<0.0001). By multiple regression analysis H(e) levels were positively correlated with male gender (p<0.02), age (p<0.001), and negatively with folic acid (p<0.0001). By logistic regression the independent predictors of carotid atherosclerosis were male gender (OR 2.65), hypertension (OR 2.55), age (x10 years, OR 2.15) and H(e) levels (x1 micromol/L, OR 1.11). This study confirmed homocyst(e)ine is associated with carotid atherosclerosis. Consequently the authors recommend H(e) levels be screened in all patients at risk for atherosclerosis.

Age Factors↗

PubMed1995

Effect of low-dose oral triphasic contraceptives on blood viscosity, coagulation and lipid metabolism.

The purpose of the study was to determine the relationship between hemorheological profile, i.e. blood viscosity, and other risk factors for cardiovascular and thrombotic diseases in women taking oral contraceptives and if blood viscosity may be considered a marker of cardiovascular risk in OC users. Plasma levels of coagulation parameters, serum lipids, blood viscosity and RBC deformability were determined in a group of 10 women taking OC vs. 10 controls. The blood parameters were evaluated before OC use and thereafter at 3 and 6 months. A significant change in the partial thromboplastin time, fibrinogen, HDL and apolipoprotein A-I was observed, while the other parameters remained unchanged. Plasma viscosity was significantly increased during OC treatment; whole blood viscosity and RBC deformability remained unchanged. However, although some parameters were significantly modified during OC treatment, all alterations remained within the normal range of laboratory values. The data confirm that low-dose triphasic OC therapy does not affect significantly the coagulation system, serum lipid metabolism and blood viscosity. Plasma viscosity measurement may be considered as a marker for monitoring women using OC because it is apparently the most sensitive parameter.

Adolescent↗

PubMed1994

Human leucocyte-endothelial interactions in peripheral arterial occlusive disease.

This ex vivo study determined the expression of leucocyte adhesion receptors for endothelial adhesion molecules in 10 patients with peripheral arterial occlusive disease (PAOD) and in 10 healthy controls before and after treadmill exercise. Granulocytes from venous blood samples were separated on a Ficoll-Hypaque gradient and the phenotypical expression of CD11a/CD18 (LFA-1), CD11b/CD18 (Mac-1) and CD11c/CD18 (p150,95) was observed by double indirect immunofluorescence using specific monoclonal antibodies. The total and differential white blood cell counts were monitored before and after exercise. In the PAOD patients a significant reduction in the number of granulocytes expressing CD11b/CD18 (Mac-1) and CD11c/CD18 (p150,95) associated with a significant neutropenia was observed after exercise, suggesting that leucocyte-endothelial interactions occur during ischaemia.

Adult↗

PubMed1994

Treating peripheral arterial occlusive disease: pentoxifylline vs exercise.

The effects of three months therapy with Pentoxifylline (800 mg three times daily) and physical training were compared in two age- and sex-matched groups of Stage II PAOD patients. Before therapy and after 12 and 13 weeks each patient underwent a standard treadmill test. The maximum walking time, TcPO2 half recovery time to basal values after the induced ischaemia, granulocyte production of free radicals (by the superoxide dismutase-inhibitable reduction of ferricytochrome) and surface expression of the CD11/CD18 complex of adhesion molecules (by using specific monoclonal antibodies) were determined. Pentoxifylline inhibited free radical production and reduced the percentage of granulocytes expressing adhesion receptors while exercise had no significant effect on these parameters. These changes, which reflect improved microcirculatory functioning, were associated with a greater walking capacity and shorter half recovery time (+14% vs exercise group, p < 0.01; -39% vs exercise group, p < 0.01 respectively).

Aged↗

PubMed1992

Leucocytes and free radicals in stable angina pectoris.

Bicycle ergometer exercise was used to induce ischemia in 20 patients with stable angina pectoris (SAP). Superoxide dismutase (SOD) blood concentrations, free radical generation (by the SOD-inhibitable reaction of ferricytochrome C), malondialdehyde (MDA) plasma concentrations, the unfractionated leucocyte filterability rate and the filterability rates of the granulocyte and mononuclear sub-fractions (using a positive pressure filtration system and 5 mu diameter Nuclepore filters), were monitored before and after exercise in the patients and in 18 matched controls. At the onset of ischemia a significant increase in the level of MDA plasma concentrations and significant decreases in both SOD blood concentrations and the SOD-inhibitable reduction of ferricytochrome C indicated oxygen free radicals had been released in the SAP patients. These changes were associated with significant impairments of granulocyte and unfractionated leucocyte filterabilities and with morphological evidence of granulocyte activation.

Aged↗

PubMed1991

Use of pentoxifylline as an inhibitor of free radical generation in peripheral vascular disease. Results of a double-blind placebo-controlled study.

The effects of an infusion of pentoxifylline 1 g as an inhibitor of free radical generation have been determined in a double-blind placebo-controlled study. Leucocyte-derived free radical generation (by the superoxide dismutase-inhibitable reduction of ferricytochrome), the release of reactive oxygen metabolites (as plasma oxidant activity), unfractionated leucocyte and erythrocyte filterability rates (using a constant-flow positive-pressure system), plasma viscosity, and plasma fibrinogen concentration have been measured in two matched groups of 10 patients with Stage II peripheral vascular disease, before and after treatment. Transcutaneous oxygen pressure (PtcO2) during treadmill exercise to stress leg circulation was also measured. Leucocyte-derived free radicals were generated during peripheral ischaemia. Pentoxifylline inhibited their generation, blocked the release of reactive oxygen metabolites, and reduced impairment of the filterability rate of unfractionated leucocytes. The improvements were accompanied by significant shortening of the half-time of recovery of transcutaneous oxygen pressure, indicating that ischaemic damage had been contained.

Cross-Sectional Studies↗

PubMed1991

Blood rheology during bacterial infection in the elderly and early middle-aged.

The aim of this study was to ascertain if the hemorheological profiles in 35 elderly and 20 young to middle-aged patients returned to normal after bacterial infection. Erythrocyte sedimentation rates, fibrinogen levels, plasma viscosity, hematocrit, white blood cell count and filterability rates (through 5 mu diameter pore filters, using a low shear positive pressure Nuclepore filtration system) of red blood cells and unfractionated leucocytes were determined at the onset of acute bacterial infection, after 3 weeks at full clinical recovery, and again 2 weeks later at the end of convalescence. Our data confirm that rheological impairments exist at the onset of bacterial infection, and persist up to clinical recovery. At the end of convalescence the unfractionated leucocyte filterability rate was still significantly higher in the elderly patients, compared not only to our normal standard, but also to average values in the younger group.

Adult↗

PubMed1991

Are leucocyte-derived free radicals involved in ischaemia in human legs?

Leucocyte-derived free radicals were monitored in 30 stage II peripheral vascular disease (PVD) patients in an open placebo-controlled study. Linked to a transcutaneous oxygen pressure (TcPO2) monitor, they performed two consecutive standard treadmill tests (5 min, 2 km h-1, 12% slope) before and after 15-days treatment with placebo or a leucocyte-derived free radical scavenger (Piroxicam, 20 mg day-1), the second test being carried out at the TcPO2 half-recovery time. Blood samples were collected at baseline, at the maximum walking times and the TcPO2 half recovery times. The total and differential leucocyte counts, the percentage of cells with pseudopodia or cytoplasmatic irregularities, the filterability rates (using a positive pressure Nuclepore filter system) of the main leucocyte subfractions and plasma oxidant activity were monitored. Compared with values before treatment and with the placebo-treated group Piroxicam therapy significantly (P less than 0.001) reduced the final half-recovery time, the percentage of cells with pseudopodia and the level of plasma oxidant activity (P less than 0.01) and kept the granulocyte filterability rate stable, showing leucocyte-derived free radicals are involved in peripheral ischaemia.

Exercise↗

PubMed1991

Efficacy of low-molecular-weight heparin in the management of intermittent claudication.

Treating chronic arterial occlusive disease with heparin is controversial because of the risks associated with long-term anticoagulant therapy. Low molecular weight (LMW) heparin (mw about 5000 Dalton), which selectively inhibits the Xa factor with minimal risk of hemorrhage, seems to offer new possibilities in the prevention and treatment of both venous and acute arterial thromboembolism. Therefore, 44 patients with intermittent claudication were recruited to a randomized, double-blind, controlled study. Twenty-two were treated for six months with a single daily subcutaneous dose (15,000 UaXa) of LMW heparin and 22 with placebo administered in the same way over the same period of time. After six months, LMW heparin treatment not only improved walking capacity (by lengthening the pain-free walking time by 25%) but also significantly modified the hemorrheologic pattern (by reducing fibrinogen concentrations and whole blood viscosity at low shear rates). LMW heparin also exerted an antithrombotic and profibrinolytic effect by significantly increasing both the anti-Xa factor and plasminogen activity without markedly modifying activated partial thromboplastin time (+20%). No LMW heparin-treated patient hemorrhaged or reported other noteworthy side effects. These results suggest LMW heparin might be a useful drug in the long-term treatment of chronic arterial occlusive disease of the limbs.

Aged↗

PubMed1991

Bacterial infection and peripheral vascular disease.

Whole blood filterability was monitored in 16 nondiabetic peripheral vascular disease (PVD) patients within forty-eight hours of onset of bacterial infection, after ten to seventeen days antibiotic therapy and again, ten days later, after convalescence. The whole blood filterability rate was constantly disturbed before infection in these patients; the impairment worsened significantly (as was expected during infection), but after convalescence the whole blood filterability rate did not return to preinfection levels. This further significant impairment in whole blood filterability was inversely correlated with a reduction in the patients' pain-free walking time as determined by a standard treadmell test performed after convalescence and compared with their average times before infection.

Bacterial Infections↗

PubMed1991

Whole-blood filterability in sudden deafness.

Sixteen patients with sudden deafness (SD), diagnosed on the basis of a battery of audiometric tests, but with no other medical or surgical pathology requiring drug treatment, underwent monitoring of their hemorheological profiles to see whether disturbances in the microcirculation could be linked to SD. Plasma viscosity, the filterabilities, (using a low-shear positive pressure system) through 5-microns-diameter pore Nuclepore filters, of whole blood and red and unfractionated white cells were monitored in 16 SD patients and 32 controls matched for age, sex and socioeconomic status. Whole blood filterability and the filterability of the red blood cells were significantly impaired in the SD patients, which suggests that alterations in the microcirculation are linked, in some way, to sudden deafness.

Adult↗