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P L Capecchi

Publications and source records attributed to P L Capecchi.

At least 19 recordsLinked to original sources
PubMed2004

Simvastatin reduces MMP-3 level in interleukin 1beta stimulated human chondrocyte culture.

OBJECTIVES: Matrix metalloproteinases (MMPs) produced by chondrocytes play a role in the development of cartilage degradation in joint diseases. Moreover, inhibition of MMP secretion by macrophages accumulating in arteriosclerotic plaques would account for the plaque stabilising activity of statins in cardiovascular patients. Recently, simvastatin has been shown to inhibit both developing and established collagen induced arthritis in a murine model. We thus decided to investigate the effect of simvastatin on the production of MMP-3 from cultured interleukin (IL)1 stimulated human chondrocytes. METHODS: Cells from human cartilage, obtained from eight subjects with osteoarthritis undergoing surgery for total hip prostheses, were cultured in the presence of different concentrations of simvastatin (5, 10, and 50 micromol/l) with and without IL1beta (5 ng/ml). MMP-3 level was measured in the culture medium after 48 h of incubation. RESULTS: IL1beta stimulation of chondrocytes increased MMP-3 concentration in the cultures (from 0.69 (0.09) to 1.94 (0.12) ng/microg protein). Incubation with simvastatin was associated with a dose dependent reduction in MMP-3 increase, both in the presence (-15%, -17%, and -26% with 5, 10, and 50 micromol/l, respectively) and in the absence (-32% with 50 micromol/l) of IL1beta. The inhibiting effect of simvastatin was completely reversed by the addition of mevalonate (100 micromol/l) or farnesol (10 micromol/l). CONCLUSIONS: Our data show that simvastatin, by blocking HMGCoA-reductase and interfering in the prenylation processes, is able to inhibit MMP-3 production from cultured human chondrocytes that have been either unstimulated or stimulated with IL1beta, thus suggesting a possible additional mechanism for statins in counteracting chronic joint disease related cartilage damage.

Aged↗
PubMed2003

ECP-treated lymphocytes of chronic graft-versus-host disease patients undergo apoptosis which involves both the Fas/FasL system and the Bcl-2 protein family.

Chronic graft-versus-host disease (cGVHD) is a severe and frequent complication of allogenic bone marrow transplantation which is often treated with extracorporeal photochemotherapy (ECP) with a positive clinical outcome in patients resistant to conventional protocols. The mechanism of action of ECP has not been fully elucidated, although several authors have reported that it is able to induce apoptosis. Using samples obtained from ten cGVHD patients, we sought to determine whether lymphocytes treated with ECP underwent apoptosis and, above all, the mechanisms involved. Lymphocytes at four stages were isolated: immediately before ECP, from the last buffy coat collected, after UV irradiation prior to reinfusion, and the day after ECP. When cultured for 48 h, lymphocytes treated with ECP underwent accelerated apoptosis (tested as annexin V binding cells and as intracellular histone-associated DNA fragments) in comparison with lymphocytes from the other samples. This enhanced programmed cell death could not be prevented by IL-2. Immediately after isolation, there was no difference in Bcl-2 or bax expression among the four different samples, or in Fas and FasL mRNA. However, when cultured, lymphocytes treated with ECP showed a rapid downregulation of Bcl-2, an upregulation of bax with an increased bax/Bcl-2 ratio, a decrease in bcl-2 mRNA and an increase in Fas. No changes were detectable in lymphocytes from the other samples. IL-2 and TNF-alpha production was not significantly different among lymphocytes from the four samples. In conclusion, in patients affected by cGVHD, ECP induced apoptosis of lymphocytes with the involvement of both the Fas/FasL system and the Bcl-2 protein family.

Adult↗
PubMed2003

Blunted increase in plasma adenosine levels following dipyridamole stress in dilated cardiomyopathy patients.

BACKGROUND: Heart failure is characterized by chronically increased adenosine levels, which are thought to express a protective anti-heart failure activation of the adenosinergic system. The aim of the study was to assess whether the activation of adenosinergic system in idiopathic dilated cardiomyopathy (IDC) can be mirrored by a blunted increase in plasma adenosine concentration following dipyridamole stress, which accumulates endogenous adenosine. METHODS: Two groups were studied: IDC patients (n = 19, seven women, mean age 60 +/- 12 years) with angiographically confirmed normal coronary arteries and left ventricular ejection fraction <35%; and normal controls (n = 15, six women, mean age 68 +/- 5 years). Plasma adenosine was assessed by high-performance liquid chromatography methods in blood samples from peripheral vein at baseline and 12 min after dipyridamole infusion (0.84 mg kg-1 in 10 min). RESULTS: At baseline, IDC patients showed higher plasma adenosine levels than controls (276 +/- 27 nM L-1 vs. 208 +/- 48 nM L-1, P < 0.001). Following dipyridamole, IDC patients showed lower plasma adenosine levels than controls (322 +/- 56 nM L-1 vs. 732 +/- 250 nM L-1, P < 0.001). The dipyridamole-induced percentage increase in plasma adenosine over baseline was 17% in IDC and 251% in controls (P < 0.001). By individual patient analysis, 18 IDC patients exceeded (over the upper limit) the 95% confidence limits for normal plasma adenosine levels at baseline, and all 19 exceeded (below the lower limit) the 95% confidence limits for postdipyridamole plasma adenosine levels found in normal subjects. CONCLUSION: Patients with IDC have abnormally high baseline adenosine levels and--even more strikingly--blunted plasma adenosine increase following dipyridamole infusion. This is consistent with a chronic activation of the adenosinergic system present in IDC, which can be measured noninvasively in the clinical theatre.

Adenosine↗
PubMed2002

Enhanced apoptosis of peripheral blood mononuclear cells in cardiac transplanted patients undergoing chronic immunosuppressive treatment.

Apoptosis plays a major role in tissue transplantation because intact T-cell-apoptosis pathways are required for the induction of tolerance to allografts. Moreover, immunosuppressive agents commonly used in clinical transplantation medicine promote lymphocyte apoptosis inhibiting the expression and production of cytokines involved in lymphocyte survival. The aim of our study was to evaluate peripheral blood mononuclear cells (PBMC) spontaneous apoptosis in patients undergoing chronic immunosuppressive treatment after cardiac transplantation. PBMC obtained from patients (n = 31) and controls matched for age and sex (n = 25) were cultured for 72 h and apoptosis was evaluated by quantification of fragmented DNA, staining with Hoechst 33258 dye and annexin V binding. We also investigated Fas expression and FasL mRNA expression as well as the ability of an IgM anti-Fas antibody to induce apoptosis. Finally, we evaluated IL2 production induced by PHA and the ability of IL2 to prevent apoptosis. In patients, PBMC underwent enhanced spontaneous apoptosis in comparison with controls. However, we could not find any difference between patients and normals as regards the expression of Fas and of FasL mRNA, even if the cross-linking of the Fas molecule induced apoptosis in PBMC from patients, whereas it failed to induce cell death in normals. We also found that IL2 production was significantly decreased in patients and that the addition of IL2 to the culture medium reduced PBMC spontaneous apoptosis. Our findings suggest that in cardiac transplanted patients PBMC undergo enhanced spontaneous apoptosis, which may contribute to prevent allograft rejection.

Adult↗
PubMed2002

Acute effects of glibenclamide on reactive hyperaemia in the lower limbs in humans.

Three episodes of 1 min ischemia in the lower limbs in humans reduced the metabolic debt repayment (expressed as AUC of reactive hyperaemia) following more prolonged ischemia (666.6+/-86.6 vs 500.0+/-33.5 ml/100 ml). The administration of the ATP-dependent K(+) channel blocker glibenclamide was associated with a significant reduction in the AUC of reactive hyperaemia (666.6+/-86.6 vs 563.1+/-76.6 ml/100 ml), and with the removal of the protective effect produced by 3 episodes of 1 min ischemia (563.1+/-76.6 vs 551.8+/-71.3 ml/100 ml). Plasma level of glibenclamide reached the peak value of 1.295+/-0.15 micromol/l 2 h after drug administration, ranging around the 1 micromol/l concentration in the following 3 hours. Our findings produce indirect evidence that, similarly to the ischemic preconditioning of the heart, the protective effects towards ischemia of brief repeated episodes of sub-maximal occlusion in the peripheral circulation of the lower limbs in humans are mediated by ATP-dependent K(+) channels.

Adult↗
PubMed2001

Effects of alprostadil on blood rheology and nucleoside metabolism in patients affected with lower limb chronic ischaemia.

The acute (0.57 microg/kg i.v. in 2 hours) and long-term (0.57 microg/kg i.v. in 2 hours for 5 days over 4 weeks) effects of the PGE1 analogue alprostadil were studied in patients affected with intermittent claudication. Whole Blood Viscosity (WBV), Whole Blood Filterability (WBF), haematocrit (Htc) and fibrinogen plasma concentration, were studied together with P50, 2,3-diphosphoglycerate, and adenosine plasma levels. Moreover, in the long-term study, pain-free (PFWD) and maximal walking distance (MWD) were measured. Single alprostadil infusion induced an improvement in WBV, WBF, and oxygen transport, and an increase in adenosine plasma levels. Long-term alprostadil administration produced a decrease in WBV only, without significant changes in WBF, Htc, fibrinogen, P50, 2,3-diphosphoglycerate, also inducing a significant prolongation of PFWD and MWD. The possibility is suggested that pulse rises in adenosine plasma levels play a role in the effects of chronic alprostadil administration, maybe in a way similar to that observed in the phenomenon of ischaemic preconditioning,

Alprostadil↗
PubMed2000

Effects of dipyridamole and adenosine on vasoactive peptides calcitonin gene-related peptide and atrial natriuretic peptide in humans: role of sympathetic activation.

1. It has been observed that dipyridamole (DIP) administration produces equivalent cardiovascular effects at lower systemic adenosine (ADO) plasma concentrations than those obtained with exogenous ADO infusion. This observation led to the identification of DIP for additional 'ischaemia-inducing' mechanisms, possibly based on sympathetic activation. 2. In turn, exogenous ADO administration has proven to elicit a complex neurohumoral response, including an increase in the plasma concentration of catecholamines, associated with augmented levels of the vasoactive peptides calcitonin gene-related peptide (CGRP) and atrial natriuretic peptide (ANP). More particularly, increases in CGRP seem to be dependent on sympathetic activation, while changes in ANP do not. 3. In order to clarify some aspects of the activity of DIP on neurohumoral systems, the effects of administration of DIP and ADO on plasma levels of noradrenaline (NA), CGRP and ANP were studied in healthy volunteers. Haemodynamic parameters were also monitored. 4. Infusion of exogenous ADO produced plasma levels of ADO as high as 1893+/-386 nmol/L, together with a significant increase in plasma levels of CGRP, ANP and NA. Similarly, the infusion of DIP produced augmented plasma concentrations of the examined parameters, with a peak plasma ADO concentration of 470+/-49 nmol/L. 5. At a given ADO plasma concentration of 450+/-10 nmol/L, the increase in CGRP and NA levels with DIP infusion was significantly higher than that observed following the infusion of ADO, whereas the increase in the plasma concentration of ANP following DIP infusion was very similar to that seen following ADO infusion. 6. The physiological background of these findings is based on evidence that DIP displays a greater sympathoexcitatory activity than does exogenous ADO and only the increase in plasma CGRP seems to be mediated, although indirectly, by beta-adrenoceptor stimulation. The exact mechanism of DIP-dependent sympathetic activation remains to be elucidated.

Adenosine↗
PubMed2000

Adenosine and chronic ischemia of the lower limbs.

Adenosine is an endogenous nucleoside with multiple biological properties which plays a central role in the pathophysiology of tissue ischemia. Adenosine signals an imbalance between oxygen demand and supply, and it initiates responses to redress such a discrepancy. Besides its vasodilating properties, adenosine possesses anti-platelet and anti-neutrophil activities and provides cytoprotection. Adenosine is presumably the main mediator of the preconditioning phenomenon. During ischemia of the lower limbs, adenosine plays a physiological role by inducing vasodilatation and by preventing microcirculatory failure. Exercise training prolongs claudication distance possibly by inducing pulse increases of adenosine and consequently skeletal muscle preconditioning. Moreover, the adenosine increase which follows the administration of some drugs, such as buflomedil and propionylcarnitine, opens new perspectives in the management of leg ischemia. In fact, the concept arises of an ischemic (exercise-dependent) or pharmacologic preconditioning in the treatment of patients with claudication.

Adenosine↗
PubMed1999

Systemic adenosine increase during cold pressor test is dependent on sympathetic activation.

1. Following local vasoconstriction-inducing stimuli, such as the cold pressor test (CPT), significant changes occur in haemodynamics, with a rise in arterial blood pressure and heart rate (HR) due to the activation of the sympathetic nervous system. Among the compensatory mechanisms to local ischaemia, the endogenous nucleoside adenosine (ADO) has been suggested to play a relevant role by contributing to sympathetic stimulation. The possibility was investigated that CPT-induced increases in plasma ADO levels were not only an expression of the increased production of ADO in the ischaemic area, but also a consequence of systemic sympathoexcitatory mechanisms, thus showing a bidirectional involvement of the mechanisms of ADO formation. 2. The CPT was performed in 15 volunteers and mean arterial blood pressure (MABP) and HR were evaluated, together with plasma levels of noradrenaline (NA) and ADO in the tested and contralateral arm. The 15 subjects were then divided into three groups of five that were treated with either 5 mg transdermal clonidine weekly, 100 mg atenolol daily or 600 mg aminophylline twice daily. After 1 week treatment, the same test was repeated in the respective groups. 3. The CPT induced a rise in MABP and HR and an increase in plasma levels of NA and ADO. Increases in ADO were more pronounced in the tested arm. Clonidine blunted the haemodynamic response and NA release, while increases in ADO increase were reduced to a greater extent in the contralateral arm rather than the tested arm. Atenolol only affected MABP and HR without any effect on NA and ADO levels. Theophylline did not show any effect on CPT-induced changes. 4. In conclusion, local vasoconstriction and ischaemia induced in one arm following CPT are associated with haemodynamic changes dependent on the activation of the sympathetic system. The observed increase in plasma levels of ADO seems to be, in part, a direct expression of local responses to ischaemia (pre-dominant in the tested arm), but also appears as the consequence of systemic sympathoexcitatory mechanisms. Such increases in ADO are not dependent on a beta 1-adrenoceptor-mediated mechanism. Finally, theophylline, at a therapeutic dose, has no effect on the response to CPT.

Adenosine↗
PubMed1998

[Usefulness of blood and plasma viscosity measurements in the evaluation of arteriopathic patients].

Blood viscosity represents the internal friction of the blood, in other terms, its resistance to be deformed and to flow under a tangential force. This function is conditioned by the intrinsic characteristics of blood and the geometry of the system in which flow occurs. Thus, any in vitro (or ex vivo) system of measurement of blood viscosity represents a relatively approximate evaluation of the ratio between intertial forces and viscous resistance. However, the possibility of measuring blood viscosity in a reproducible way provided the opportunity of identifying some clinical conditions associated with a worsening in rheologic parameters. Thus, "primary" and "secondary" hyperviscosity syndromes have been defined, on the basis of the pathogenetic responsibility of rheologic or hemodynamic factors, respectively. The possibility of performing in vitro measurement of blood viscosity provided the opportunity of planning several clinical pharmacology studies with theoretically active drugs. On such a basis, the rationale has arisen for a "rheologic therapy" of circulatory disturbances. Moreover, the evaluation of rheologic parameters is extremely useful since epidemiological studies have shown that viscosity may represent a marker and a prognostic factor for the progression of ischemic diseases as well as an independent risk factor, thus suggesting the opportunity of performing controlled clinical studies to evaluate the impact of hemorheological changes in the prevention of cardiovascular events.

Blood Flow Velocity↗
PubMed1997

Experimental model of short-time exercise-induced preconditioning in POAD patients.

Regular physical exercise improves walking performance in patients affected with peripheral obliterative arterial disease (POAD). The mechanisms underlying the phenomenon are still controversial. In order to verify the hypothesis that physical conditioning of lower limbs on a treadmill and ischemic preconditioning of the heart could share some biological aspects, 14 POAD subjects underwent a training program on the treadmill consisting of five repeated submaximal exercises at five-minute and two-hour intervals preceding the maximal tolerance test. Moreover, a protocol with two daily submaximal walking exercises over one week was also performed. Pain-free and total walking distance were measured before and after they performed the program. Moreover, plasma levels of adenosine and adenosine triphosphate (ATP) were measured and polymorphonuclear (PMN) leukocyte activity was studied together with rheologic parameters. Pain-free distance was prolonged by 15.4% and 14.3%, and total distance was prolonged by 23.1% and 26.9%, in the exercises with five-minute and two-hour intervals, respectively. After one week of daily exercises, the onset of pain and the end of the test were delayed by 24% and 43.7%, respectively. An improvement in blood rheology and a reduced PMN reactivity were also observed with the three protocols, associated with an increase in plasma levels of adenosine and ATP. Similarly to ischemic preconditioning in the heart, the possibility is suggested that an adenosine-mediated mechanism may contribute to the development of physical conditioning in treadmill-trained POAD patients.

Adenosine↗
PubMed1997

Carnitines increase plasma levels of adenosine and ATP in humans.

In order to help to clarify the mode of action of carnitine derivatives, plasma levels of adenosine, ATP and inosine were evaluated following the infusion of 0.75, 0.50 and 0.25 mg/kg/min propionyl-L-carnitine (PLC) for 30 min in patients affected with peripheral arterial disease. Moreover, the effects of 0.75 mg/kg/min acetyl-L-carnitine (ALC) and L-carnitine (LC) were studied in the same conditions. Finally, the activity of 7.5 mg/kg/min PLC administered for 3 min was also evaluated. PLC and ALC produced a significant increase in plasma levels of adenosine and ATP, whereas LC induced less relevant changes. The administration of the compounds did not affect the adenosine/inosine ratio. Peak plasma levels of adenosine preceded in any case those of ATP. The possibility can be suggested that the pharmacological activity of PLC, ALC, and LC may be mediated, at least in part, by an interference with the endogenous purine system. Since these effects may be related to physiological mechanisms of tissue protection, new pharmacological perspectives for the compounds may arise.

Acetylcarnitine↗