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Biomedical subjects

F Bruni

Publications and source records attributed to F Bruni.

At least 37 records · Page 2Linked to original sources
PubMed2002

Time-dependent effect of statins on platelet function in hypercholesterolaemia.

BACKGROUND: Reduction of platelet activity induced by statins has been described as a positive effect exerted by such molecules on vascular thrombotic events. However, the relations among cholesterol (LDL-C) reduction, the timing of the antiplatelet effect, the involved mechanisms and the doses of each statin able to reduce platelet function are not actually well known. The aim of our study was to evaluate the impact of simvastatin (20 mg day-1), atorvastatin (10 mg day-1), fluvastatin (40 mg day-1) and pravastatin (40 mg day-1) on platelet function in hypercholesterolaemic subjects with relation to (LDL-C), oxidized-LDL (ox-LDL) and antiport mechanism modifications. MATERIALS AND METHODS: Sixteen subjects were assigned to each treatment (40 males, 24 females, mean age 48.7 +/- 13.4, LDL-C 5.13 +/- 0,23 mmol L-1) and evaluated for platelet surface P-selectin (P-sel), lipid profile, ox-LDL, platelet-associated ox-LDL (Pox-LDL), platelet cholesterol content, antiport mechanisms, and intracellular and systemic NO synthase every 7 days for one month. RESULTS: Our data show a strong relation between enhanced P-sel and Pox-LDL (r = 0.68, P < 0.01). Simvastatin, atorvastatin, fluvastatin and pravastatin reduce platelet activity after 1, 2, 3 and 4 weeks of treatment, respectively (P < 0.001, P < 0.001, P < 0.01, P < 0.05). Pox-LDL are modulated early by simvastatin, atorvastatin and fluvastatin Pox-LDL (r = 0.66, 0.65 and 0.52; P < 0.001, 0.001 and 0.01, respectively) whereas LDL-C and ox-LDL reductions associated to modifications of antiport activity act later. Moreover, they are the most relevant finding in pravastatin-related subjects. CONCLUSIONS: Our data suggest a different impact of several statins on platelet function, which is initially related to interference with Pox-LDL rather than LDL-C reduction.

Adult↗
PubMed2002

[Pathophysiology of congestive heart failure].

Pathophysiology of congestive heart failure (CHF) has undergone a remarkable evolution during the last two decades. CHF is now regarded especially as a neurohormonal disease and not only as a cardiocirculatory impairment. Many studies have emphasized that an abnormal neuroendocrine activation precedes the development of clinically recognized heart failure and plays an important pathogenetic role in progression of this disease. In patients with CHF, moreover, circulating levels of some neurohormonal factors have an independent negative prognostic value. More recently immunological and molecular biology studies have also demonstrated the negative effects exerted by some cytokines and by apoptosis. Correction of neurohormonal disorder is the rationale of therapeutical approach to patients with CHF and appears the only way to significantly decrease mortality. In this review the role of neuroendocrine activation in the pathophysiology of CHF is analyzed.

Angiotensin II↗
PubMed2001

Glassy dynamics and enzymatic activity of lysozyme.

There has been much interest in the analogies between dynamic processes in proteins and in other complex systems such as viscous liquids and glasses. We have investigated the dynamics of protons along chains of hydrogen-bonded water molecules adsorbed on the surface of the globular protein lysozyme. The hydration dependence of the dielectric relaxation time is fitted by a modified Vogel-Fulcher-Tamman equation, in which the variable temperature has been replaced with hydration. We find that the relaxation time diverges at a singular hydration that coincides with the critical water content required to trigger lysozyme enzymatic activity. This surprising correlation suggests a direct coupling between protein function and glasslike behavior, with possible implications for the turnover number of the enzyme.

Biophysical Phenomena↗
PubMed2001

2-Arylpyrazolo[1,5-a]pyrimidin-3-yl acetamides. New potent and selective peripheral benzodiazepine receptor ligands.

A new class of N,N-diethyl-(2-arylpyrazolo[1,5-a]pyrimidin-3-yl)acetamides (3f-y), as azaisosters of Alpidem, was prepared following a novel synthetic method and their affinities for both the peripheral (PBR) and the central (CBR) benzodiazepine receptors were evaluated. Binding assays were carried out using both [3H]PK 11195 and [3H]Ro 5-4864 as radioligands for PBR, whereas [3H]Ro 15-1788 was used for CBR, in rat kidney and rat cortex, respectively. The tested compounds exhibited a broad range of binding affinities from as low as 0.76 nM to inactivity and most of them proved to be high selective ligands for PBR. The preliminary SAR studies suggested some of the structural features required for high affinity and selectivity; particularly the substituents on the pyrimidine moiety seemed to play an important role in PBR versus CBR selectivity. A subset of the highest affinity compounds was also tested for their ability to stimulate steroid biosynthesis in C6 glioma rat cells and some of these were found to increase pregnenolone formation with potency similar to Ro 5-4864 and PK 11195.

Acetamides↗
PubMed2001

Effect of diet and treatment with statins on platelet-dependent thrombin generation in hypercholesterolemic subjects.

BACKGROUND AND AIM: Platelets are strictly involved in arterial thrombosis and their hyperactivity has been shown in hypercholesterolemia. It has been reported that drugs affecting cholesterol metabolism (statins) decrease cardiovascular events by lowering lipid levels or by means of non-lipidic actions such as the direct inhibition of platelet function. The aim of this study was to detect the effect on platelet-dependent thrombin generation (PDTG) of a reduction in cholesterol obtained by means of a lipid-lowering diet or treatment with statins. METHODS AND RESULTS: We compared PDTG (T0) in 144 hypercholesterolemic subjects (94 males and 50 females of child-bearing age, mean age 48.2 +/- 13.8, plasma total cholesterol 6.93 +/- 0.64, high density lipoprotein cholesterol 1.25 +/- 0.14, triglycerides 1.15 +/- 0.19 mmol/L) and 70 normolipidemic controls (37 males and 33 females, mean age 43.1 +/- 12.6. After six weeks on an appropriate diet, the patients were randomised to receive different statin therapies if there was no reduction in their lipid profile and/or PDTG (T1). They were re-evaluated six weeks later, and the drug doses were maintained or increased on the basis of the variables (T2). A final evaluation was made after a further six weeks (T3). All of the data were evaluated using ANOVA and Spearman's correlation coefficent. The results showed increased PDTG in hypercholesterolemic subjects (418.2 +/- 29.2 mIU/mL, p < 0.001 vs controls). Diet alone did not reduce PDTG (380.2 +/- 28.5 mIU/mL, p = 0.226 vs controls). At T2, simvastatin and atorvastatin significantly decreased PDTG (P < 0.001 vs T0-1) and low-density lipoprotein cholesterol (LDL-C). No correlation was found between the two variables in the simvastatin group (r = 0.16). Cerivastatin reduced PDTG without significantly decreasing LDL-C (p < 0.001 and p = 0.476, r = 0.14). Pravastatin and fluvastatin significantly reduced thrombin generation only at T3 (40 mg/day); pravastatin was also associated with a decrease in LDL-C (p < 0.01, r = 0.66). CONCLUSIONS: Our results confirm an increased PDTG in patients with type IIa hyperlipoproteinemia, which is not reduced by diet. Statins at different doses significantly decrease PDTG but do not correlate with a reduction in LDL-C.

Adult↗
PubMed2001

Different mechanisms of fibrinolysis impairment among dyslipidemic subjects.

To determine whether there is a correlation between fibrinolytic activity and dyslipidemia, we performed a study of 72 subjects (20 patients with hypercholesterolemia, 20 with hypertriglyceridemia, 12 with isolated low high-density lipoprotein (HDL)-cholesterol (mean age 47.7 +/- 6.3, body mass index 24.7 +/- 0.4) and 20 healthy controls. Plasminogen activator inhibitor-1 (PAI-1), tissue-plasminogen activator activity and plasmin-antiplasmin complexes (PAP) were detected at baseline and after venous occlusion test. We also measured at baseline lipidic pattern, soluble E and P selectins (sE-sel, sP-sel), prothrombin factor 1+2 (F1+2), lipoprotein(a), factor VII, plasma insulin, fibrinogen, homocysteine, and thrombin activable fibrinolysis inhibitor (TAFI) activity. Fibrinolysis was significantly reduced in hypertriglyceridemic patients compared with hypercholesterolemic patients and control subjects (PAP, p < 0.01 and p < 0.001) and was associated with increased PAI-1 (at baseline and after venous occlusion test, p < 0.001). sP-sel, F1 +2 and TAFI were not significantly different compared with controls, while hypercholesterolemic subjects showed a significant increase in these parameters (p < 0.001), which were related to decreased PAP only at the upper low-density lipoprotein (LDL)-cholesterol levels (>160 mg/dl) (p < 0.001, r = -0.76). Moreover, there was no significant difference in PAI-1 activity (at baseline and after venous occlusion test) compared with controls. In conclusion, endothelial dysfunction was the main mechanism of decreased fibrinolysis in subjects with hypertriglyceridemia and low HDL-cholesterol, while enhanced thrombin generation and TAFI activity were the main determinants in hypercholesterolemia.

Adult↗
PubMed2000

Role of platelets in tissue factor expression by monocytes in normal and hypercholesterolemic subjects. In vitro effect of cerivastatin.

Thrombosis is a complication of atherosclerosis and monocytes play a determinant role either in the progression of atherosclerotic plaque or in blood coagulation by way of tissue factor expression. Platelets play a direct role in thrombosis and a hyperfunctional state has been described in hypercholesterolemic subjects. Moreover, platelets seem to be able to enhance monocyte activity. Cholesterol-lowering molecules (statins) are reported to reduce cardiovascular risk, either by decreasing the circulating level of cholesterol or by non-lipidic actions such as the reduction of monocyte and platelet activity. The aim of our study was to investigate the influence of platelets on the expression of tissue factor by monocytes and the effect induced by cerivastatin. We measured tissue factor levels by ELISA and the procoagulant activity of stimulated monocytes by a clotting assay on cellular preparations and whole blood in 40 hypercholesterolemic subjects (22 male, 18 female, mean age 52.7 +/- 12 years, total cholesterol 251.6 +/- 19.9 mg/dl) before and after cerivastatin addition. Tissue factor expression was enhanced in hypercholesterolemic subjects compared with normal subjects (31.6 +/- 7.6 vs. 23 +/- 5.8 pg/cells, P < 0.01). The presence of platelets increased the amount of tissue factor (55.3 +/- 7.3 pg/cells, P < 0.001) and cerivastatin reduced the expression of tissue factor in isolated monocytes, in the mixed cellular system, and in whole blood (19.6 +/- 4.1 pg/cells, P < 0.001). In conclusion, tissue factor expression by monocytes is enhanced in hypercholesterolemic subjects compared with normal controls. Platelets enhance monocyte production of tissue factor, and cerivastatin is able to counteract this prothrombotic mechanism.

Adult↗
PubMed2000

Complement activation in hypercholesterolemia.

BACKGROUND AND AIM: Inflammatory and lipid factors share an important role in atherosclerosis. This study evaluates their relations in dyslipidemic subjects. METHODS AND RESULTS: We compared the complement system (serum hemolytic activity CH50, C3 and C4 fractions and terminal complex sC5b-9) in 30 hypercholesterolemic patients with elevated cholesterol and decreased HDL-cholesterol levels, 30 normolipemic patients with clinical atherosclerosis and 30 matched normal subjects. In addition we evaluated the circulating immune complexes containing cholesterol (chol-CIC) on the assumption that they might be important in complement activation, and the circulating levels of the adhesion molecule ICAM-1 (sICAM-1) as a sign of endhotelial dysfunction. We found a significant increase of sC5b-9 (but not of CH50 and C3, C4) in the hypercholesterolemics compared with the other groups. The plasma sC5b-9 level was inversely and significantly related to HDL-chol (regression analysis), whereas no direct significant relation was found between sC5b-9 and cholesterol. Chol-CIC were also significantly increased in this group. The atherosclerosis patients also presented a significant increase of sC5b-9. Lastly, both patient groups displayed a significant increase of sICAM-1. CONCLUSIONS: We suggest that complement activation in dyslipidemics may be induced by their increased immune complexes. However, the decrease of complement regulatory proteins carried by HDL is another important factor, while complement changes may be related to variations of other humoral and cell systems (endothelium, coagulative/fibrinolytic system), whose involvement is suggested in our study by the changes of sICAM-1.

Adult↗
PubMed2000

[Evolution in the pharmacological treatment of venous thrombosis according to evidence-based medicine].

Today therapeutic protocols must be in accordance with Recommendations derived by Randomized Controlled Trials (RCT) Evidences. Deep Venous Thrombosis (DVT), post-thrombotic syndrome and pulmonary embolism (PE) are different forms of the thromboembolic venous disease. The Authors, according with Evidence-Based Medicine, review the most significant RCT about Low-Molecular-Weight Heparin (LMWH). It has been proved that LMWH is more efficacious, easier to administrate and with less significant side effects than Unfractioned Heparin (UH) in DVT treatment. Its higher anti-Xa than anti-IIa activity provides higher anti-thrombotic properties and lower haemorrhagic risk. LMWH does not require anticoagulant monitoring and allows outpatient--ambulatory care. RCT also showed lower PE ratio and lower haemorrhagic risk with LMWH outpatient care than with UH in-hospital care for DVT. RCT showed also a long-term lower DVT relapse and PE incidence with LMWH than with oral anticoagulants. The Authors report their own experience with LMWH and early ambulation for the treatment of DVT versus standard UH therapy. Their retrospective analysis confirms lower incidence of complications: growth of the thrombus, severe haemorrhages, PE.

Acute Disease↗
PubMed1999

Benzodiazepine receptor ligands. III. Synthesis and biological evaluation of 2- and/or 3-substituted pyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides.

A new series of 2- and/or 3-substituted pyrazolo [5,1-c][benzotriazine 5-oxides and their 8-chloro derivatives were synthesized, and their benzodiazepine receptor (BZR) affinities were evaluated in vitro in comparison to lead compound 3-ethoxycarbonyl-8-chloropyrazolo[5,1-c][1,2,4]benzotriazine 5-oxide (29) [1,2]. None of the new compounds showed significant affinity for BZR. On the basis of a pharmacophore/receptor model suggested for lead compound 29, some hypotheses to explain the inactivity of new derivatives are discussed.

Animals↗
PubMed1999

Benzodiazepine receptor ligands. 4. Synthesis and pharmacological evaluation of 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxides.

The synthesis of new 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2, 4]benzotriazine 5-oxides and their binding activities at the central benzodiazepine receptor (BZR) are reported. The derivatives substituted at the 3-position with electron-rich five-membered rings, such as pyrrole 11, 2-thiophene 13c, or 3-thiophene 13d, showed good affinity values for BZR. In in vivo tests the 3-(thien-3-yl)-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxide (13d) showed selective anticonvulsant activity.

Animals↗
PubMed1999

Proton glass freezing in hydrated lysozyme powders.

At room temperature, the dielectric relaxation of hydrated powder of the protein lysozyme is known to be due to protons migrating between ionized side chains. A recent study of this relaxation at lower temperatures suggested a behavior typical of proton glasses. An analysis of the complex dielectric susceptibility by a temperature-frequency plot presented here has revealed that ergodicity is broken due to the divergence of the longest relaxation time at 266 K, indicating specifically that this hydrated protein is a proton glass. A change in the temperature behavior of the static dielectric constant and the average relaxation frequency at 273 K indicates a further transition occurring at this temperature, whose nature remains to be investigated.

Freezing↗
PubMed1998

POEMS syndrome with vascular lesions and renal carcinoma - possible role of cytokines.

We describe here the case of a 60 years man with POEMS syndrome associated with renal tumor and vascular lesions. The patient had osteosclerotic myeloma IgA-lambda, polyneuropathy, endocrinopathy and skin changes. In addition, he developed renal clear cell carcinoma and gangrena of lower limbs. The humoral study showed thrombocytosis, high levels of IL-1beta and IL-6 and of some coagulative/fibrinolytic and endothelial factors (von Willebrand factor, plasmin-antiplasmine complexes, plasminogen activator). We suggest the hypothesis that these factors are capable of determining some manifestations of POEMS syndrome.

Adenocarcinoma, Clear Cell↗
PubMed1998

POEMS syndrome with vascular lesions: a role for interleukin-1beta and interleukin-6 increase--a case report.

The authors describe the case of a 60-year-old man with POEMS syndrome associated with vascular lesions. The patient had osteosclerotic myeloma IgA (lambda), polyneuropathy, endocrinopathy, and skin changes. Subsequently, he developed gangrene of the lower limbs with no response to heparin therapy. The humoral study showed thrombocythemia, high levels of interleukin-1beta (IL-1beta) and IL-6 and of some coagulative/fibrinolytic and endothelial factors (von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator, and endothelial adhesion molecule ICAM-1). The authors suggest that these factors, induced by the increased levels of cytokines, could be responsible for microvascular damage, gangrene, and heparin resistance.

Fibrinolytic Agents↗
PubMed1997

The in vitro effect of Pidotimod on some immune functions in cancer patients.

There are several reports concerning an impairment of cellular immune response in patients affected by malignant disease. The aim of this study was to evaluate the in vitro effect of Pidotimod, a synthetic biological response modifier, on some immune functions in 14 cancer patients. In particular, we showed that these subjects had a significantly reduced peripheral blood mononuclear cell (PBMC) proliferation both in response to PHA and to Con A in comparison with a group of healthy subjects. Besides, they showed a significantly reduced PBMC IL2 production, which was evaluated both through an ELISA method and a biological assay. The in vitro addition of increasing concentrations of Pidotimod (10, 25 and 50 ug/ml) was able to enhance PBMC proliferation and IL2 production significantly. However, in spite of the addition of Pidotimod, both immune functions in our neoplastic patients did not reach normal values.

Adjuvants, Immunologic↗
PubMed1997

Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones. II. Synthesis and in vitro antimicrobial evaluation.

A series of Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (4a-p) was prepared by a simple synthetic procedure based on the reaction of hydroxylamine or methoxyamine with 2,3-substituted ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (3a-p). The antimicrobial activity of the obtained compounds was evaluated on a series of standard strains of Gram positive, Gram negative bacteria and fungi. None of the tested compounds showed significant activity.

Anti-Bacterial Agents↗