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1.
J Theor Biol ; 492: 110203, 2020 05 07.
Article in English | MEDLINE | ID: mdl-32067938

ABSTRACT

Tissue self-organization into defined and well-controlled three-dimensional structures is essential during development for the generation of organs. A similar, but highly deranged process might also occur during the aberrant growth of cancers, which frequently display a loss of the orderly structures of the tissue of origin, but retain a multicellular organization in the form of spheroids, strands, and buds. The latter structures are often seen when tumors masses switch to an invasive behavior into surrounding tissues. However, the general physical principles governing the self-organized architectures of tumor cell populations remain by and large unclear. In this work, we perform in-vitro experiments to characterize the growth properties of glioblastoma budding emerging from monolayers. We further propose a theoretical model and its finite element implementation to characterize such a topological transition, that is modelled as a self-organised, non-equilibrium phenomenon driven by the trade-off of mechanical forces and physical interactions exerted at cell-cell and cell-substrate adhesions. Notably, the unstable disorder states of uncontrolled cellular proliferation macroscopically emerge as complex spatio-temporal patterns that evolve statistically correlated by a universal law.


Subject(s)
Neoplasms , Cell Adhesion , Cell Division , Humans , Mechanical Phenomena , Models, Theoretical
2.
J Clin Pharm Ther ; 32(5): 477-82, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17875114

ABSTRACT

BACKGROUND: Adipose tissue is not an inert deposit of fat; in the truncal area, it seems to be metabolically active, due to the adipokines produced locally. These substances are related to insulin resistance, inflammation and atherosclerotic damage to the vascular system. The development of ultrasound methodologies enable better estimation of fat distribution and more detailed investigation of the metabolic aspects of the fat depots and their impact on the initial stages of atherosclerosis. AIM OF THE STUDY: To investigate the influence of abdominal fat on endothelial function, the initial stages of atherosclerotic vascular damage and its relationship with inflammatory status in normal-overweight subjects [n. 162, body mass index (BMI) >25 kg/m(2) to <30 kg/m(2)]. METHODS: A total of 162 Caucasian postmenopausal women (mean age 54 +/- 4 years, menopausal age 8 +/- 4 years) were subdivided on the basis of the median value of the visceral fat distribution and associations with brachial flow-mediated vasoactivity (FMV), BMI, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), total and LDL cholesterol investigated. RESULTS: Subjects with lower levels of visceral fat had a higher brachial FMV (7.9 +/- 4.3 vs. 5.1 +/- 3.2%, P < 0.05) and lower BMI, waist, sICAM-1, sVCAM-1, total and LDL cholesterol. In univariate analyses, abdominal visceral fat showed a direct correlation with sICAM-1 (r = 0.43, P < 0.001), and an inverse correlation with FMV (r = -0.49, P < 0.01). Moreover an indirect relationship emerged between brachial FMV and sICAM-levels (r = -0.36, P < 0.05). In a multivariate analysis the predictive variables for brachial FMV were LDL cholesterol (beta = -0.22, P < 0.05), visceral fat (beta = -0.32, P < 0.05), sICAM-1 (beta = -0.18, P < 0.05), HDL cholesterol (beta = 0.25, P < 0.05) and brachial diameter (beta = -0.27, P < 0.05). Subcutaneous fat and triglycerides were also included in the model. CONCLUSIONS: In Caucasian normal-overweight women, visceral fat thickness was directly associated with the level of soluble ICAM-1 and inversely with FMV, thereby showing its relevance to endothelial function and the inflammatory state.


Subject(s)
Abdominal Fat/physiopathology , Endothelium, Vascular/physiopathology , Obesity/metabolism , Postmenopause , Analysis of Variance , Anthropometry , Body Fat Distribution , Body Mass Index , Brachial Artery/physiopathology , Cholesterol, LDL/blood , Female , Humans , Intercellular Adhesion Molecule-1/blood , Middle Aged , Obesity/physiopathology , Regional Blood Flow , Vascular Cell Adhesion Molecule-1/blood
3.
J Clin Pharm Ther ; 32(4): 373-9, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17635339

ABSTRACT

BACKGROUND: Resistin could be the linkage between the adipose tissue and the insulin resistance. In humans, the role of resistin on metabolic and vascular homeostasis is not well defined. The aim of this study was to investigate the possible association between resistin expression and insulin resistance. METHODS AND RESULTS: We evaluated the relationship between monocyte expression of mRNA and anthropometric and metabolic parameters of insulin resistance. We focused on the potential role of resistin on endothelial function. Thirty-nine patients with metabolic syndrome (MS) and clinically free from cardiovascular disease, and 15 healthy subjects were included in this study. All subjects underwent clinical examination, assessment of haematochemical parameters, bioimpedentiometry, measurement of monocyte resistin mRNA and of brachial-artery flow-mediated vasodilation (FMV). Patients with MS showed higher levels of interleukin-6 (IL; 2.1 +/- 1.2 vs. 1.2 +/- 0.9 pg/mL, P < 0.05) and reduced FMV (5.4 +/- 3.9 vs. 8.3 +/- 3.1%, P < 0.05). The subjects were divided into two groups: (i) subjects with high expression mRNA resistin levels and (ii) subjects with low or not detectable; Group 1 was younger (50 +/- 13 vs. 59 +/- 11 years, P = 0.01), showed higher IL-6 values (2.3 +/- 1.2 vs. 1.6 +/- 1.2, P = 0.03) and lower values of FMV (4.3 +/- 2.8 vs. 7.4 +/- 3.9%, P = 0.003). With univariate analysis monocyte mRNA showed a significant positive correlation with waist circumference (r = 0.27, P < 0.05) and IL-6 (r = 0.26, P < 0.05) and a negative correlation with FMV (r = -0.38, P < 0.005). With multivariate regression analysis brachial-artery diameter, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, IL-6 and RNAm resistin expression were independent predictors of reduced FMV. CONCLUSIONS: mRNA resistin negatively influences FMV, and is a possible in vivo index of endothelial dysfunction.


Subject(s)
Gene Expression , Insulin Resistance/genetics , RNA, Messenger/metabolism , Resistin/metabolism , Adult , Aged , Body Weights and Measures , Brachial Artery , Cholesterol, HDL , Cholesterol, LDL , Endothelium, Vascular , Female , Humans , Interleukin-6/metabolism , Male , Metabolic Syndrome/physiopathology , Middle Aged , Monocytes , Regional Blood Flow , Resistin/genetics , Vasodilation/physiology
4.
Vasa ; 35(4): 215-20, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17109362

ABSTRACT

BACKGROUND: The natriuretic peptides, Brain Natriuretic Peptide (BNP), C-type Natriuretic Peptide (CNP), are mediators of cardiovascular homeostasis. The impairment of arterial ability to vasodilate, also known as endothelial dysfunction, represents the first stage of atherosclerotic damage and may be assessed as brachial flow mediated vasodilation (FMV) in human. Generally an altered brachial FMV is documented in association to several cardiovascular risk factors as hypercholesterolemia. Aim of the study was to evaluate the behaviour of BNP and CNP in hyperlipemia and the potential relationship to FMV. PATIENTS AND METHODS: Forty-four hyperlipemic patients (LDL-cholesterol > 130 mg/dl and/or triglycerides > 150, age 35-60 y) of both genders and 20 normolipemic patients, matched for age and sex were investigated. RESULTS: Patients had lower values of brachial FMV in comparison to controls (3.9 +/- 3.5 vs 7.5 +/- 0.5%, p < 0.005), no differences were observed in BNP (4.6 +/- 4.6 vs 5.9 +/- 3.4 ng/mL, p = n.s) and CNP (4.1 +/- 5.8 vs 5.7 +/- 3.3 ng/mL, p = n.s). Univariate analysis showed a positive correlation between BNP and HDL-cholesterol values (r = 0.36, p = 0.001). In the multivariate analysis, LDL-cholesterol (beta = -0.57), HDL-cholesterol (beta = 0.26) and brachial artery diameter (beta = -0.33) were predictors of brachial FMV. The only predictive variable for CNP was HDL-cholesterol (beta = 0.37). CONCLUSIONS: The present study suggested that natriuretic peptides, BNP and CNP, are not altered in patients affected by hypercholesterolemia. Nevertheless, the levels of HDL-cholesterol are strictly related to the values of CNP. This observation, in humans, adds another mechanism to the vascular control exerted by HDL.


Subject(s)
Atherosclerosis/blood , Cholesterol, HDL/blood , Endothelium, Vascular/physiopathology , Hypercholesterolemia/blood , Natriuretic Peptide, Brain/blood , Natriuretic Peptide, C-Type/blood , Vasodilation/physiology , Adult , Blood Flow Velocity/physiology , Brachial Artery/physiopathology , Cholesterol, LDL/blood , Female , Humans , Male , Middle Aged , Risk Factors , Statistics as Topic , Triglycerides/blood
6.
J Hand Surg Br ; 31(3): 280-4, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16403425

ABSTRACT

For many years, bipedicled palmar advancement flaps were used rarely in fingers because they sacrificed the dorsal branches of the digital arteries, risking dorsal skin necrosis. In 1995, a short bipedicled neurovascular VY advancement flap raised distally to the PIP flexion crease, which spared the dorsal blood supply, was described by Elliot et al. (1995). This paper includes an anatomical study on 28 fresh cadaver fingers to evaluate the advancement potential of this flap. It also reviews 22 fingertip reconstructions in 22 patients using this flap. The mean advancement of the flap in the cadaver study was 14 (range 10-16) mm. This procedure gave good clinical results in respect of healing, sensibility, bone cover and appearance. Complications occurred in four fingers (18%), viz. two infections, one neuroma and one stiff proximal interphalangeal joint. Our study suggests that this flap can be used to treat fingertip defects of a size of approximately half of the pulp of the distal phalangeal segment of the finger.


Subject(s)
Finger Injuries/surgery , Fingers/surgery , Surgical Flaps , Adolescent , Adult , Cadaver , Child , Child, Preschool , Finger Injuries/physiopathology , Humans , Middle Aged , Postoperative Complications , Range of Motion, Articular/physiology , Retrospective Studies , Sick Leave/statistics & numerical data , Touch/physiology , Treatment Outcome
7.
Reumatismo ; 57(1): 16-21, 2005.
Article in Italian | MEDLINE | ID: mdl-15776142

ABSTRACT

BACKGROUND: There is an increasing body of evidence suggesting that subjects with rheumatoid arthritis (RA) are characterized by acceleration of atherosclerotic process of arterial wall. However, all investigations performed so far to evaluate subclinical atherosclerosis in RA included subjects without selection for age and degree of disease activity that may represent confounding factors in such an evaluation. OBJECTIVES: To verify signs of accelerated subclinical atherosclerosis in young subject suffering from RA but with low disease activity. METHODS: Thirty-two patients with RA and 28 age- and sex-matched control subjects with non-inflammatory rheumatic diseases were enrolled. Inclusion criteria were age less than 60 and low disease activity with score < or =3.2 according to DAS28, while subjects with traditional risk factors for and/or overt cardiovascular disease were ruled out from the study. Both patients and controls underwent evaluation of carotid and femoral artery intima-media thickness by ultrasounds. RESULTS: Patients had higher intima-media thickness than controls of all the sites evaluated at carotid artery level, whereas there were no differences at the comparison of the superficial and common femoral artery wall. At the univariate analysis, a positive correlation between LDL cholesterol levels and intima-media thickness at the carotid bifurcation was found. CONCLUSIONS: Young patients with RA and low disease activity have acceleration of atherosclerosis development as shown by increased intima-media thickness of carotid artery with respect to subjects without inflammatory rheumatic disease. It is conceivable that the organic damage of arterial wall could be the result of persistent endothelial dysfunction induced by chronic inflammation and immune dysregulation which characterize RA.


Subject(s)
Arthritis, Rheumatoid/complications , Atherosclerosis/complications , Atherosclerosis/diagnosis , Female , Humans , Male , Middle Aged
8.
Ann Rheum Dis ; 63(1): 31-5, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14672888

ABSTRACT

BACKGROUND: Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease. Endothelial dysfunction represents the earliest stage of atherosclerosis. OBJECTIVE: To evaluate the influence of chronic inflammatory state on endothelial function in patients with RA by measuring endothelial reactivity in young patients with RA with low disease activity and without traditional cardiovascular risk factors. METHODS: Brachial flow mediated vasodilatation (FMV), assessed by non-invasive ultrasound, was evaluated in 32 young to middle aged patients with RA (age /=4 determinations multiplied by the disease duration (r = -0.40, p<0.05). In a multivariate regression model, a lower brachial flow mediated vasodilatation was independently predicted by low density lipoprotein cholesterol (beta = -0.40, p<0.05), average CRP levels multiplied by the disease duration (beta = -0.44, p<0.05), and brachial artery diameter (beta = -0.28, p<0.05). CONCLUSIONS: Young to middle aged patients with RA with low disease activity, free from cardiovascular risk factors and overt cardiovascular disease, have an altered endothelial reactivity that seems to be primarily related to the disease associated chronic inflammatory condition.


Subject(s)
Arthritis, Rheumatoid/physiopathology , Endothelium, Vascular/physiopathology , Adult , Analysis of Variance , Arthritis, Rheumatoid/complications , Brachial Artery/physiopathology , Cardiovascular Diseases/etiology , Case-Control Studies , Female , Humans , Male , Middle Aged , Regional Blood Flow , Risk Factors , Vasodilation
9.
J Clin Pharm Ther ; 28(5): 419-24, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14632967

ABSTRACT

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.


Subject(s)
Cell Adhesion Molecules/blood , Dietary Fats/blood , Fasting/blood , Fenofibrate/therapeutic use , Hypertriglyceridemia/drug therapy , Hypolipidemic Agents/therapeutic use , Postprandial Period/drug effects , Adult , Endothelium, Vascular/drug effects , Female , Fenofibrate/pharmacology , Humans , Hypolipidemic Agents/pharmacology , Male , Middle Aged , Vasodilation/drug effects
10.
Vasa ; 32(3): 139-43, 2003 Aug.
Article in English | MEDLINE | ID: mdl-14524033

ABSTRACT

BACKGROUND: Patients with peripheral arterial disease (PAD) are characterized by a high mortality for cardiovascular events. An impairment of endothelial function, expressed as brachial-artery flow-mediated vasodilation (FMV), has been described in PAD patients. Aim of this study was to investigate the association between FMV and cardiovascular events in patients with PAD. PATIENTS AND METHODS: Thirty-eight patients with intermittent claudication (71% men, mean age 71 years) were divided into two groups according to the presence or absence of previous major cardiovascular events (myocardial infarction or stroke). RESULTS: Brachial FMV was significantly lower in patients with a history of myocardial infarction or stroke (n = 16) than in patients without cardiovascular events (3.2 +/- 3.6% vs. 5.7 +/- 3.6%; p = 0.042). In the group with cardiovascular events there was a significantly higher proportion of subjects in the lower FMV tertile (56% vs. 18%), and a lower proportion of subjects in the upper tertile (25% vs. 41%; chi 2 test, p = 0.047). CONCLUSION: We conclude that FMV of the brachial artery is significantly reduced in PAD patients with a history of stroke and myocardial infarction. These cross-sectional results suggest a potential role of FMV as a marker of major cardiovascular events.


Subject(s)
Arterial Occlusive Diseases/physiopathology , Cerebral Infarction/physiopathology , Endothelium, Vascular/physiopathology , Myocardial Infarction/physiopathology , Aged , Arterial Occlusive Diseases/diagnostic imaging , Blood Flow Velocity/physiology , Brachial Artery/diagnostic imaging , Brachial Artery/physiopathology , Cerebral Infarction/diagnostic imaging , Endothelium, Vascular/diagnostic imaging , Humans , Intermittent Claudication/diagnostic imaging , Intermittent Claudication/physiopathology , Male , Middle Aged , Myocardial Infarction/diagnostic imaging , Recurrence , Reference Values , Risk Assessment , Ultrasonography, Doppler , Vasodilation/physiology
11.
Ann Hum Genet ; 66(Pt 1): 37-48, 2002 Jan.
Article in English | MEDLINE | ID: mdl-12014999

ABSTRACT

For this study we consulted the Bone Marrow Donors' Registry of Lombardy (Italy) and analyzed 43937 HLA-A,B phenotypes and 13922 HLA-A,B,DR phenotypes. We estimated the HLA-A,B and HLA-A,B,DR haplotype frequencies via the maximum-likelihood method. We analyzed the genetic structure of the 11 provinces of Lombardy by means of Principal Component Analysis and Correspondence Analysis, and estimated the variety of the different haplotypes at provincial level and the percentage of unique phenotypes at village level. We found 11189 different HLA-A,B phenotypes, 661 different HLA-A,B haplotypes and more than 4000 different HLA-A,B,DR haplotypes. We identified 20 villages, in Western Lombardy, very rich in unique/rare phenotypes. Here we report a formula which allows the identification of a putative donor matched for two haplotypes with a recipient. This result may be of great importance for the genetic study of the population of Lombardy and, even more, for bone marrow transplantation programs.


Subject(s)
Bone Marrow Transplantation , Bone Marrow/immunology , HLA Antigens/genetics , HLA-DR Antigens/genetics , Haplotypes , Histocompatibility Testing/methods , Tissue Donors , Alleles , Gene Frequency , HLA Antigens/immunology , HLA-A Antigens/genetics , HLA-A Antigens/immunology , HLA-B Antigens/genetics , HLA-B Antigens/immunology , HLA-DR Antigens/immunology , Humans , Immunogenetics , Italy , Phenotype , Polymorphism, Genetic , Registries , Rural Population
12.
Ann Nutr Metab ; 46(1): 32-7, 2002.
Article in English | MEDLINE | ID: mdl-11914513

ABSTRACT

BACKGROUND/AIM: Postmenopausal age is characterized by a higher risk for coronary heart disease (CHD) and postprandial lipemia is strictly related with the evidence of CHD. The aim of the study was to clarify the vascular effects of postprandial state in postmenopausal women. METHODS: Ten postmenopausal women (mean age 57 +/- 8 years) without vascular risk factors and history of cardiovascular disease underwent an oral fat load test. Endothelial function, expressed as brachial flow-mediated vasodilation (FMV), lipid parameters and reduced glutathione (GSH) were evaluated at baseline and 2, 4 and 6 h after the load. RESULTS: FMV showed a significant decrease at the 2nd hour (2.3 +/- 2.6%, vs. baseline 7.7 +/- 2.8%, p < 0.05) and overlapping to the basal value after 4 h. Triglycerides increased postprandially at the 2nd and 4th hour (1.6 +/- 0.6 micromol/l, 1.8 +/- 0.5 micromol/l vs. baseline 0.9 +/- 0.4 micromol/l, p < 0.05), decreasing thereafter. GSH decreased at the 2nd hour of the postprandial phase (5.1 +/- 1.9 micromol/l vs. baseline 8.4 +/- 1.9 micromol/l, p < 0.05), normalizing successively. At the univariate analysis a negative correlation was found between FMV and triglyceride changes (r = -0.37, p < 0.05) and a positive one between FMV and GSH modifications (r = 0.40, p < 0.05). CONCLUSION: These data demonstrated that postprandial lipemia transiently impairs endothelial reactivity by an oxidative burden, partly dependent to triglyceride increase.


Subject(s)
Dietary Fats/pharmacology , Endothelium, Vascular/drug effects , Glutathione/metabolism , Lipids/blood , Postprandial Period/physiology , Brachial Artery/diagnostic imaging , Brachial Artery/drug effects , Brachial Artery/physiology , Coronary Disease/etiology , Dietary Fats/administration & dosage , Endothelium, Vascular/physiology , Female , Humans , Middle Aged , Postmenopause/metabolism , Risk Factors , Triglycerides/blood , Ultrasonography , Vasodilation/drug effects
13.
Am J Hypertens ; 14(10): 1025-31, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11710781

ABSTRACT

Large artery intima-media thickness (IMT) is considered an integrated marker for the total individual burden of arteriosclerosis, and a graded index for cardiovascular risk. However, several different aggregate indexes of IMT on B-mode ultrasound have been used by various investigators, and the optimal number of IMT readings is currently unsettled. In 128 newly diagnosed, never treated, uncomplicated hypertensive subjects aged <55 years (43 +/- 9 years, blood pressure [BP] 152/99 mm Hg), we measured left ventricular mass (M-mode echocardiography, average of five or more measurements) and IMT of common carotid and common femoral arteries. For each segment, 12 IMT measurements were performed, and the average of 1 and 3 readings (right far wall), 6 readings (right side), and 12 readings (right and left side, far and near wall, 3 sampling points) was analyzed. The relation of IMT with left ventricular mass increased progressively with increasing number of readings, from 0.35 (1 reading) to 0.51 (12 readings) for common carotid artery, and from 0.31 to 0.56 for common femoral artery (both P <.001). For each 0.2-mm increase in common femoral IMT, the age-adjusted relative risk of having left ventricular hypertrophy was 1.31 for 1 reading, and increased up to 3.59 for the average of 12 readings. In summary, the association of IMT with left ventricular mass depends strongly on the number of IMT readings. The average of several readings in each segment, including right and left side and far and near wall, carries the closest association to left ventricular mass, and should be preferred for clinical purposes in hypertensive subjects.


Subject(s)
Carotid Artery, Common/diagnostic imaging , Carotid Artery, Common/pathology , Femoral Artery/diagnostic imaging , Femoral Artery/pathology , Hypertension/diagnostic imaging , Hypertension/pathology , Tunica Intima/diagnostic imaging , Tunica Intima/pathology , Adult , Arteriosclerosis/etiology , Biomarkers , Cardiovascular Diseases/etiology , Echocardiography/methods , Female , Heart Ventricles/diagnostic imaging , Heart Ventricles/pathology , Humans , Hypertension/complications , Hypertrophy , Male , Middle Aged , Risk Factors , Ultrasonography/methods
14.
J Clin Pharm Ther ; 26(5): 343-9, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11679024

ABSTRACT

BACKGROUND: Endothelial dysfunction is considered the earliest stage of atherosclerosis. Postprandial phase is associated with a transient impairment of endothelial function concomitantly with the triglyceride-rich lipoprotein increase. This phenomenon may be explained by the oxidative burden induced by triglyceride-rich lipoproteins, reducing nitric oxide bioavailability. OBJECTIVE: To investigate the effect of a diet enriched with L-arginine, the substrate for nitric oxide synthesis on endothelial function in healthy volunteers. METHODS: Endothelial function (expressed as flow-mediated vasodilation (FMV) of the brachial artery), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, LDL-size, Lp (a) and reduced glutathione (GSH) were evaluated in seven healthy males (mean age 23 +/- 3 years) without cardiovascular risk factors. Measurements were made at baseline and 2, 4 and 6 h after a standardized oral fat load. L-arginine (6 g daily) was administered for 10 days. On the 11th day the oral fat load and the parameters examined previously at entry were repeated. RESULTS: After the first oral fat load, FMV significantly decreased at 2 and 4 h, and overlapped with the basal levels at 6 h. After L-arginine treatment, FMV significantly decreased at 2 h and normalized after 4 and 6 h. Triglycerides increased at 2 and 4 h and decreased after 6 h in both sets of observations relating to before and after L-arginine administration. GSH dropped 2 h after the fat load, both before and after L-arginine. Before L-arginine, FMV exhibited a significant correlation with triglycerides (r= -0.426, P= 0.024) and GSH (r=0.48; P=0.009). After L-arginine, FMV was related to GSH (r=0.39; P=0.03) but not to triglycerides (r= -0.12; P=0.52). CONCLUSION: Postprandial endothelial impairment is partly abolished by L-arginine administration. These data, which require confirmation, suggest the importance of dietary choice for atherosclerosis prevention even in young healthy subjects.


Subject(s)
Arginine/administration & dosage , Brachial Artery/physiology , Dietary Supplements , Endothelium, Vascular/physiology , Adult , Arginine/blood , Brachial Artery/diagnostic imaging , Brachial Artery/drug effects , Cardiovascular Diseases/prevention & control , Dietary Fats/administration & dosage , Endothelium, Vascular/diagnostic imaging , Endothelium, Vascular/drug effects , Fasting , Glutathione/blood , Humans , Insulin/blood , Lipids/blood , Male , Postprandial Period , Risk Factors , Time Factors , Ultrasonography , Vasodilation/drug effects
16.
Metabolism ; 50(3): 330-4, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11230787

ABSTRACT

The increased risk for coronary artery disease observed in postmenopausal women is partly explained by a more atherogenic fasting lipoprotein profile. Moreover, natural menopause has been associated with an altered postprandial lipid profile. To better characterize the interaction between fasting and postprandial lipid profile after menopause, we examined postprandial changes in several lipid parameters in three age-matched groups of postmenopausal women (16 affected by mixed hyperlipemia, 17 by common hypercholesterolemia, and 17 normolipemic), who underwent a standardized oral fat-loading test. The magnitude of postprandial lipemia, expressed as 8-hour triglyceride incremental area under the curve, was greater in women with mixed hyperlipemia (1,326 +/- 372 mg x dL(-1) x h(-1)) than in normal (484 +/- 384 mg x dL(-1) x h(-1)) and hypercholesterolemic (473 +/- 223 mg x dL(-1) x h(-1); both P <.0001) women, and the differences held after adjustment for body mass index and fasting insulin. Women with mixed hyperlipemia showed a significant postprandial decrease in high-density lipoprotein 2 (HDL(2)) cholesterol, lipoprotein (a), and low-density lipoprotein (LDL) particle size. Both hypercholesterolemic and normolipemic women showed a significant postprandial decrease in HDL cholesterol and lipoprotein (a) levels but not in LDL size. In a multiple linear regression analysis, fasting triglyceride levels, insulin level, and waist-hip ratio were all independent predictors of the magnitude of postprandial lipemia. In conclusion, postmenopausal women with mixed hyperlipemia show a greater postprandial triglyceride increase and a more pronounced reduction in HDL cholesterol level and LDL size than hypercholesterolemic and normolipemic subjects. The presence of the features of insulin resistance syndrome could contribute to the deterioration of postprandial lipemic response in these subjects.


Subject(s)
Hypercholesterolemia/complications , Hyperlipidemias/complications , Lipids/blood , Postmenopause/blood , Postprandial Period , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Dietary Fats/administration & dosage , Dietary Fats/pharmacology , Female , Humans , Hypercholesterolemia/blood , Middle Aged , Reference Values , Triglycerides/blood
17.
J Cardiovasc Pharmacol ; 36(5): 617-21, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11065222

ABSTRACT

Endothelial dysfunction represents the earliest stage of atherosclerosis and is usually present in hypercholesterolemia. Treatment with statins has been shown to normalize endothelial function in middle-aged men with hypercholesterolemia. We evaluated the effect over time of atorvastatin on the endothelial reactivity in postmenopausal hypercholesterolemic women (mean age, 58 +/- 6 years), receiving atorvastatin, 10 mg daily (n = 20) or American Heart Association step 1 diet (n = 10) for 8 weeks. Lipid profile and brachial artery flow-mediated vasodilation (FMV) were determined at baseline and after 1, 2, 4, and 8 weeks. FMV increased progressively in subjects treated with atorvastatin, and the difference was significant (p < 0.05 vs. baseline) after the second week (baseline 3.8 +/- 3%; first week, 4.8 +/- 3%; second week, 9.2 +/- 3%; fourth week, 11.0 +/- 3%; eighth week, 11.7 +/- 3%). No significant changes were observed in subjects receiving diet (baseline, 3.1 +/- 4%; first week, 2.4 +/- 2%; second week, 2.9 +/- 2%; fourth week, 3.1 +/- 2%; eighth week, 3.3 +/- 2%; p = NS). In the atorvastatin group, low-density lipoprotein (LDL) cholesterol showed a significant decrease since the first week (baseline, 228 +/- 37 mg/dl; first week, 171 +/- 32; second week, 147 +/- 27; fourth week, 139 +/- 29; eighth week, 135 +/- 27; all p < 0.05). In the control group, LDL cholesterol showed a smaller but significant (p < 0.05) reduction after the second week (baseline, 226 +/- 17 mg/dl; first week, 225 +/- 16; second week, 220 +/- 17; fourth week, 203 +/- 27; eighth week, 198 +/- 27). In conclusion, hypercholesterolemic women treated with atorvastatin show a significant improvement in endothelial reactivity after as early as 2 weeks of therapy. The extent to which these beneficial effects are attributable to cholesterol reduction or to a direct effect of the drug remains to be established.


Subject(s)
Anticholesteremic Agents/therapeutic use , Endothelium, Vascular/drug effects , Heptanoic Acids/therapeutic use , Hypercholesterolemia/drug therapy , Pyrroles/therapeutic use , Vasodilation/drug effects , Analysis of Variance , Atorvastatin , Cholesterol/blood , Female , Humans , Hypercholesterolemia/diet therapy , Lipoproteins/blood , Middle Aged , Postmenopause
18.
Am Heart J ; 140(3): 521-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10966556

ABSTRACT

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.


Subject(s)
Cell Adhesion Molecules/analysis , Cholesterol, LDL/analysis , Hypertriglyceridemia/pathology , Adult , Endothelium/physiology , Humans , Male , Particle Size , Vasodilation
19.
Atherosclerosis ; 153(2): 397-402, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11164429

ABSTRACT

Impaired flow-mediated vasodilation in large arteries is an expression of endothelial dysfunction and an established marker of early atherosclerosis. Post-prandial lipemia can induce an impairment of the endothelial function. The aim of our study was to evaluate the effects of post-prandial phase on flow-mediated vasodilation in a group of ten young (23 +/- 2 years) healthy men without cardiovascular risk factors, who underwent an oral fat-loading test. Flow-mediated vasodilation of the brachial artery and serum lipid profile were assessed under fasting conditions and 2, 4, 6 and 8 h after a high-fat meal. Triglycerides increased from 0.6 +/- 0.2 fasting to 1.1 +/- 0.5 and 1.3 +/-0.6 mmol/l at the 2nd and 4th hour (both P < 0.01), and decreased thereafter. Flow-mediated vasodilation fell significantly from 14.5 +/- 6.6% fasting to 3.5 +/- 1.5% and 4.0 +/- 2.2% at the 2nd and 4th hour (both P < 0.01), and returned to the basal values at the 6th and 8th hour. A strong inverse correlation was observed between the area under the incremental curve of post-prandial triglycerides (i.e. after subtraction of baseline triglycerides) and the area under the decremental curve of post-prandial flow-mediated vasodilation (r = -0.70, P = 0.025). No association was found between post-prandial vasodilation changes and fasting triglycerides, other lipid parameters or insulin. We conclude that a transient post-prandial impairment in brachial artery flow-mediated vasodilation is evident in young healthy men after a high-fat meal, and is closely associated with triglyceride levels. These data provide support for a role of post-prandial phase in vascular regulation in young healthy subjects.


Subject(s)
Postprandial Period/physiology , Vasodilation/physiology , Adult , Arteriosclerosis/etiology , Arteriosclerosis/metabolism , Arteriosclerosis/physiopathology , Dietary Fats/administration & dosage , Endothelium, Vascular/physiology , Humans , Male
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