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Biomedical subjects

M B Donati

Publications and source records attributed to M B Donati.

At least 19 recordsLinked to original sources
PubMed2006

Inhibition of tissue factor expression by hydroxyurea in polymorphonuclear leukocytes from patients with myeloproliferative disorders: a new effect for an old drug?

BACKGROUND: Polymorphonuclear leukocytes (PMN) from healthy subjects can produce and store tissue factor (TF), which is expressed on PMN surface upon in vitro stimulation with P-selectin. RESULTS: We report here that platelets and PMN from 12 patients with myeloproliferative disorders (MPD) (six with polycythemia vera, six with essential thrombocythemia) show up regulation of P-selectin and TF, respectively, in the absence of any in vitro challenge. The number of circulating mixed platelet-PMN aggregates was also increased. PMN TF expression as well as mixed platelet-PMN aggregates, but not platelet P-selectin, were significantly reduced in six MPD patients after treatment with hydroxyurea (HU). In vitro studies performed on PMN separated from healthy donors confirmed HU effects (0-1400 microm). HU prevented both P-selectin-induced TF expression and mixed cell aggregate formation. The inhibitory effect of HU was specific for P-selectin-induced PMN activation, as it did not affect formyl-methionyl-leucyl-phenylalanine-induced PMN TF expression. CONCLUSIONS: In MPD patients, platelet P-selectin-mediated TF expression on circulating PMN may play a role in thrombus formation and represents a novel target for the antithrombotic activity of HU.

Aged↗
PubMed2006

The -675 4G/5G plasminogen activator inhibitor-1 promoter polymorphism in house dust mite-sensitive allergic asthma patients.

BACKGROUND: Plasminogen activator inhibitor (PAI)-1 plays an important role in inflammation and tissue remodeling. Recently, the -675 4G/5G PAI-1 polymorphism has been linked with asthma. OBJECTIVE: This study was undertaken to evaluate associations of the -675 4G/5G PAI-1 polymorphism with functional and immunologic parameters of newly diagnosed house dust mite-sensitive allergic asthmatics (HDM-AAs). METHODS: This study was performed in 127 HDM-AAs, who responded with at least 20% fall of forced expiratory volume during the first second (FEV(1)) to a bronchial challenge with Dermatophagoides pteronyssinus allergen and during the follow up observation fulfilled GINA criteria for mild-moderate asthma. About 89 healthy control nonatopic subjects (HCs) were used as controls. RESULTS: The frequency of 4G allele was greater in HDM-AAs (0.69; 95% CI: 0.62-0.76) than in HCs (0.55; 95% CI: 0.48-0.62; P = 0.0034). The PAI-1 polymorphism was associated with an increased risk of HDM-AA; adjusted for sex and age odds ratio was 2.62; (95% CI: 1.16-5.92) for 4G/5G genotype and 3.48 (95% CI: 1.54-7.89) for 4G/4G genotype compared with 5G/5G genotype. Total serum immunoglobulin E (tsIgE) level in 4G/4G homozygotes (557 +/- 343 kU/l) was significantly greater than in 5G/5G homozygotes (241 +/- 288 kU/l; P < 0.001). Both nonspecific and allergen-specific bronchial reactivities were greater in 4G/4G homozygotes than in 5G/5G homozygotes. 4G/4G genotype was associated with significantly higher morning plasma PAI-1 concentration in HDM-AAs and HCs. Morning plasma PAI-1 concentration correlated significantly with log(PC20) (r = -0.39; P = 0.0001) and with log(tsIgE) (r = 0.247; P = 0.0117). CONCLUSION: These results support the hypothesis linking the 4G/4G PAI-1 genotype with an increased risk of allergic asthma, bronchial hyperreactivity, and increased tsIgE levels.

Adult↗
PubMed2006

Human polymorphonuclear leukocytes produce and express functional tissue factor upon stimulation.

BACKGROUND: Blood-borne tissue factor (TF) plays a crucial role in thrombogenesis. AIM: To study whether polymorphonuclear leukocytes (PMN) are a source of TF. METHODS AND RESULTS: Human PMN were carefully separated from other blood cells and stimulated for 3 min with purified P-selectin or the chemotactic peptide formyl-MetLeuPhe (fMLP): they expressed both TF procoagulant activity, as identified by specific TF MoAb and inactivated factor VIIa blockade; and TF:Ag (four to six times), as shown by flow-cytometry and immunocytochemistry. About 40% of permeabilized PMN, both resting and stimulated, contained TF:Ag, indicating that stimulation only modifies the location of TF:Ag within PMN. By real time-polymerase chain reaction (RT-PCR), a very low amount of TF mRNA was detectable in resting PMN, but a 3- to 5-fold increase was observed after 1-h stimulation with P-selectin or fMLP, respectively. CONCLUSIONS: These findings suggest that TF is not constitutively expressed in peripheral PMN, but can be up-regulated and produced upon stimulation and specific gene transcription, as for instance during contact with activated platelets or endothelium. The stored TF is rapidly expressed in vitro as a functional molecule on the surface of activated PMN. The availability of PMN TF supports the relevance of inflammatory cells and their interaction with platelets for fibrin deposition and thrombus formation.

Antibodies, Monoclonal↗
PubMed2005

P-selectin gene genotypes or haplotypes and cardiovascular complications in type 2 diabetes mellitus.

BACKGROUND AND AIM: Increased levels of sP-selectin, a member of the selectin family involved in the transient attachment of leukocytes to endothelial cells, are found in a number of conditions including diabetes and ischemic heart disease. A number of polymorphisms in the gene encoding P-selectin have been identified. The purpose of the present study was to explore the role of three non-synonymous P-selectin gene polymorphisms, Tyr715Pro, Asn562Asp and Ser290Asn, in determining the risk of macrovascular complications in type 2 diabetic patients. METHODS AND RESULTS: Following a cross-sectional case-control design from 837 Italian type 2 diabetics, 301 cases with at least one episode of angina pectoris (AP), acute myocardial infarction (AMI), stroke, transient ischemic attacks (TIA) or peripheral arterial disease (PAD) were compared with 536 controls free of ischemic vascular complications in the period preceding the examination. Case subjects had longer duration of diabetes at the time of examination and were older as compared with controls. Hypertension and male sex were over-represented among cases. Allele frequency and genotype distribution of the three polymorphic variants did not show any significant preferential association in groups of cases or controls. Odds ratios also indicated no effect on risk of cardiovascular disease even after adjustment for potentially confounding variables. There was a strong allelic association between Tyr715Pro and Asn562Asp (D' = -0.99, P < 0.0001). Ser290Asn was in linkage disequilibrium with Tyr715Pro (D' = 0.43, P = 0.15) and in almost complete equilibrium with Asn562Asp (D' = 0.05, P = 0.5). Haplotype phase inferred from genotypic data revealed the presence of 6 haplotypes. Global test of significance showed no difference in three marker haplotype distribution between cases and controls (P = 0.88, df = 5). CONCLUSIONS: The present study excludes a major contribution of Tyr715Pro, Asn562Asp and Ser290Asn P-selectin polymorphisms to a susceptibility to ischemic vascular complications in type 2 diabetes.

Aged↗
PubMed2005

Alcohol-free red wine prevents arterial thrombosis in dietary-induced hypercholesterolemic rats: experimental support for the 'French paradox'.

The concept of the 'French paradox' has been recently challenged. As it is difficult in a short period to produce direct clinical evidence of the protective effect of red wine on thrombosis, we evaluated such a possibility in an experimental model mimicking the conditions of the 'French paradox'. Normolipidemic rats (FNL) were fed a standard diet or a 2% cholesterol-rich-diet (Ch-rich-diet) for 5 months: the latter was given either alone (FNL + D) or in combination with 'alcohol-free' red wine (FNL + D + 5 W). Arterial thrombosis was measured as the occlusion time (OT) of an artificial prosthesis inserted into the abdominal aorta. Lipid levels, platelet adhesion to fibrillar collagen, factor VII (FVII) clotting activity and fibrinogen levels were also measured. Compared to animals fed a standard diet, Ch-rich diet induced in FNL rats a several-fold increase in lipids and FVII levels with a concomitant significant increase in both thrombotic tendency (shortening of the OT) and platelet adhesion. 'Alcohol-free' red wine supplementation almost completely reverted the prothrombotic effect of the Ch-rich-diet. Indeed, the OT was prolonged from 78 +/- 3 to 122 +/- 10 h (P < 0.01), while platelet adhesion to fibrillar collagen was reduced from 49 +/- 3.5% to 30 +/- 2.8%. Neither the increase in lipid levels induced by Ch-rich diet nor FVII or fibrinogen levels were modified by wine supplementation. In conclusion, in experimental animals, this study supports the concept of the 'French paradox' that regular consumption of wine (rather than alcohol) was able to prevent arterial thrombosis associated with dietary-induced hypercholesterolemia, an effect mediated by downregulation of platelet function.

Animals↗
PubMed2004

Polymorphisms of the interleukin-1beta gene affect the risk of myocardial infarction and ischemic stroke at young age and the response of mononuclear cells to stimulation in vitro.

OBJECTIVE: To investigate the role of interleukin-1beta (IL-1beta) gene polymorphisms as a link between inflammation, coagulation, and risk of ischemic vascular disease at young age. METHODS AND RESULTS: A total of 406 patients with myocardial infarction (MI) at young age, frequency-matched for age, sex, and recruitment center, with 419 healthy population-based controls and 134 patients with ischemic stroke at young age, matched by age and sex, with 134 healthy population-based controls, were studied. Subjects carrying the TT genotype of the -511C/T IL-1beta polymorphism showed a decreased risk of MI (odds ratio [OR], 0.36; 95% CI, 0.20 to 0.64) and stroke (OR, 0.32; 95% CI, 0.13 to 0.81) after adjustment for conventional risk factors. In both studies, the T allele showed a codominant effect (P=0.0020 in MI; P=0.021 in stroke). Mononuclear cells from volunteers carrying the T allele showed a decreased release of IL-1beta and a decreased expression of tissue factor after stimulation with lipopolysaccharide compared with CC homozygotes. The presence of a monoclonal antibody against IL-1beta during cell stimulation resulted in a marked reduction of tissue factor activity expression. CONCLUSIONS: -511C/T IL-1beta gene polymorphism affects the risk of MI and ischemic stroke at young age and the response of mononuclear cells to inflammatory stimulation.

Adolescent↗
PubMed2003

Resveratrol and quercetin down-regulate tissue factor expression by human stimulated vascular cells.

BACKGROUND: Epidemiological studies have shown that consumption of wine reduces the risk of coronary heart disease. Resveratrol and quercetin, two polyphenolic compounds found in grapes and red wine, have been shown to contribute to this protection by exerting several biological properties which could be associated with cardioprotection. Tissue factor (TF), the cellular receptor that initiates blood coagulation, plays a primary role both in hemostasis following tissue injury and in the pathogenesis of atherosclerosis which predisposes to thrombosis. OBJECTIVES: We investigated the role of resveratrol and quercetin on TF expression by endothelial and mononuclear cells (MN). METHODS: Confluent human umbilical vein endothelial cells and MN collected from healthy donors were stimulated with bacterial lipopolysaccharide, interleukin-1beta or tumor necrosis factor-alpha after incubation with increasing concentrations of resveratrol or quercetin. RESULTS: In both cell types, TF activity induced by any agonist was significantly reduced by resveratrol or quercetin in a dose-dependent fashion. Northern blot analysis indicated that resveratrol and quercetin strongly reduce TF mRNA in both cell types. The inhibition of TF mRNA originated from a reduction in nuclear binding activity of the transacting factor c-Rel/p65, which was induced by the agonists and measured by electromobility shift assay. Western blot analysis revealed that the diminished c-Rel/p65 activity was dependent upon inhibition of degradation of the c-Rel/p65 inhibitory protein IkappaBalpha. CONCLUSIONS: These results provide a molecular basis which could help explain the protective activity of red wine against cardiovascular disease.

Active Transport, Cell Nucleus↗
PubMed2003

A high-score Mediterranean dietary pattern is associated with a reduced risk of peripheral arterial disease in Italian patients with Type 2 diabetes.

BACKGROUND: The 'Mediterranean diet' is considered to exert protective effects on cardiovascular disease, although a wide range of dietary patterns exists among subjects living even in the same Mediterranean country. OBJECTIVE: To investigate the association between specific dietary patterns and peripheral arterial disease (PAD) in Italian Type 2 diabetes patients. DESIGN: From a cohort of 944 patients with Type 2 diabetes, 144 patients with PAD were selected, and matched for age and sex with 288 Type 2 diabetic control patients without macrovascular complications. A dietary score was elaborated from a semiquantitative food frequency questionnaire. The higher the final score, the healthier the eating habit. RESULTS: In multivariate analysis, a higher score was independently associated with a significant reduction in PAD risk [odds ratio (OR) = 0.44; 95% confidence interval (CI) 0.24, 0.83]. Diabetes duration (OR > 15 years = 2.49; 95% CI 1.45, 4.25), hypertension (OR = 2.12; 95% CI 1.31, 3.45) and butter consumption (OR = 2.6; 95% CI 1.15, 3.68) were also significantly associated with PAD. The dietary score significantly improved the predictive value of models based on duration of diabetes and hypertension. (LSR = 2.19, DF = 7, P < 0.001). The effect of a high dietary score on the risk of PAD was independent of diabetes duration and hypertension. CONCLUSION: In Italian Type 2 diabetics, a higher dietary score has a protective role against PAD. The use of butter increases the risk of PAD even in patients regularly consuming olive oil. Dietary advice may be helpful for the prevention of PAD in diabetics even in populations traditionally accustomed to a Mediterranean dietary habit.

Aged↗
PubMed2003

Homocysteine levels are associated with the severity of peripheral arterial disease in Type 2 diabetic patients.

BACKGROUND: Homocysteine levels are positively associated with the risk of cardiovascular disease. They might be determined by both MTHFR677C-->T polymorphisms and folate or B-vitamin status. OBJECTIVES: To investigate the possible association between plasma homocysteine levels and its genetic or environmental determinants and either the presence or the severity of peripheral arterial disease (PAD), in Type 2 diabetic patients. METHODS: From a cohort of 944 patients with Type 2 diabetes, 135 patients with PAD were selected, and frequency-matched for age and sex with 219 Type 2 diabetic control patients without macrovascular complications. According to the increasing severity of the disease, patients were divided into PAD1 (only diffuse calcifications of the arteries without any stenosis or occlusion), PAD2 (one or two stenosis or occlusions) and PAD3 (three or more). RESULTS: Homocysteine levels were similar in control and case patients (10.3 micromol L-1 vs. 10.7 micromol L-1, P = 0.53); however, a significant increase was found in PAD3 patients: odds ratio = 2.77 (95% confidence interval 1.14, 6.72) for patients with homocysteine levels above the median vs. those under the median in multivariate analysis. Although all significantly associated with homocysteine levels, neither MTHFR genotype nor folic acid or vitamin B12 levels were associated with severity of PAD. A significant interaction (P < 0.05) was found between folic acid and MTHFR polymorphism in determining the levels of homocysteine. CONCLUSIONS: In Type 2 diabetes, homocysteine was associated with the angiographic severity of PAD, but neither the genotypes nor vitamin levels contributed to this association.

Aged↗
PubMed2002

Effect of extra virgin olive oil on experimental thrombosis and primary hemostasis in rats.

BACKGROUND AND AIM: Olive oil is a particular source of fat in the Mediterranean diet, which is associated with a lower incidence of cardiovascular disease. We investigated the possible antithrombotic role of extra virgin olive oil as a single dietary modification in experimental thrombosis and primary hemostasis models in rats. METHODS AND RESULTS: Two different groups of animals were studied: one fed a usual diet (control group) and the other a diet enriched with extra virgin olive oil (3%; weight/weight). After six weeks feeding, arterial thrombosis was initiated by inserting an artificial prosthesis (or "aortic loop") into the aorta, and venous thrombosis was induced by ligating the inferior vena cava. "Template" bleeding time (BT) was measured, as well as factor VII coagulant activity (FVII:C) and fibrinogen levels. The animals fed the olive oil enriched diet showed a significant delay in the thrombotic occlusion of the "aortic loop" (99 +/- 5 h vs 82 +/- 5 h, p < 0.04), a lower incidence of venous thrombosis (57% vs 86%; p < 0.05) and a prolonged BT (154 +/- 7 sec vs 122 +/- 4 sec; p < 0.01) in comparison with the control group. They had lower plasma fibrinogen concentrations (209 +/- 5 mg/dL vs 233 +/- 4 mg/dL; p < 0.01) but similar FVII:C levels (119 +/- 5% vs 108 +/- 5%; p = NS) despite their lower triglyceride concentrations (52 +/- 5 mg/dL vs 79 +/- 10 mg/dL; p < 0.05). CONCLUSIONS: This study provides the first in vivo experimental evidence of the thrombosis prevention properties of olive oil, which are possibly mediated by reduced fibrinogen concentrations and impaired platelet/vessel wall interactions.

Animals↗
PubMed2001

Relation of the -174 G/C polymorphism of interleukin-6 to interleukin-6 plasma levels and to length of hospitalization after surgical coronary revascularization.

Interleukin (IL)-6 plasma levels are predictive of major cardiovascular events. The -174 G/C promoter polymorphism of the IL-6 gene affects basal levels in vivo and transcription rates in vitro, but its association with IL-6 acute phase levels among patients with coronary artery disease has not been investigated. In 111 patients with multivessel coronary artery disease undergoing elective coronary artery bypass graft surgery, we prospectively assessed genotype at position -174 and serial blood levels of IL-6 and other inflammatory indexes. Clinical and surgical characteristics did not differ among genotypic groups. IL-6 levels--measured daily up to 72 hours before surgery, after surgery, and at discharge--showed a mean 17-fold increase, peaking at 24 hours (p <0.0001). IL-6 levels (but not fibrinogen, white-blood cell count, and C-reactive protein values) differed significantly according to the -174 genotype (p = 0.042 for difference between areas under the curve), the 62 GG homozygotes exhibiting higher concentrations than the 49 carriers of the C allele (widest difference at 48 hours, p = 0.015 in multivariate analysis). GG homozygosity was associated with longer stays in the intensive care unit (2.5 +/- 3.4 vs 1.4 +/- 0.9 days, p = 0.02) and in the hospital (6.7 +/- 4.0 vs 5.3 +/- 1.4 days, p = 0.02) than C carriership. Rates of postoperative death, myocardial infarction, and stroke were 8% in GG homozygotes and 2% in C-carriers (p = 0.16). The IL-6-174 GG genotype is associated with higher acute phase levels of IL-6 and with longer stays in the hospital and in the intensive care unit than C allele carriership after surgical coronary revascularization.

C-Reactive Protein↗