Biomedical subjects

G Leoncini

Publications and source records attributed to G Leoncini.

At least 19 recordsLinked to original sources

PubMed2006

Homocysteine, reactive oxygen species and nitric oxide in type 2 diabetes mellitus.

INTRODUCTION: Type 2 diabetes mellitus shows a characteristic altered platelet function that can be due to several mechanisms such as oxidative stress. Hyperhomocysteinemia, considered as a risk factor for various arterial thrombosis, may have a role in generating oxidative damage, even if the pathogenic mechanisms are still not clear. In this report we aimed to determine the role of plasma homocysteine in inducing oxidative stress in type 2 diabetes mellitus. MATERIALS AND METHODS: The study was performed on a group of 34 males with type 2 diabetes and 36 healthy subjects matched for sex and age. Patients and healthy subjects were undergone to laboratory evaluation for plasma homocysteine levels and other metabolic parameters. In both groups of subjects platelet reactive oxygen species, nitric oxide and guanosine 3',5' cyclic monophosphate levels were measured. Moreover the reduced glutathione content in platelets of patients and of healthy subjects was assayed. RESULTS: Plasma homocysteine levels were significantly increased in patients compared with healthy subjects. The basal level of reactive oxygen species was significantly higher in patients than in controls. In addition platelets of patients stimulated with thrombin produced more reactive oxygen species than healthy subjects ones. The nitric oxide, guanosine 3',5' cyclic monophosphate and reduced glutathione content were decreased in platelets of patients. CONCLUSIONS: As homocysteine stimulates oxidative stress and inhibits nitric oxide formation, hyperhomocysteinemia measured in type 2 diabetic patients, promoting platelet hyperactivity, could have a role in the atherogenic effects described in type 2 diabetes.

Aged↗

PubMed2006

Activation of p38 MAPKinase/cPLA2 pathway in homocysteine-treated platelets.

Hyperhomocysteinemia is considered a risk factor in arterial and venous thrombosis. The mechanism by which homocysteine (HCy) supports atherothrombosis is still unknown and may be multifactorial. Earlier in vitro studies demonstrated that HCy induced arachidonic acid release and increased thromboxane B2 (TXB2) formation. In this work, we found that HCy stimulated the rapid and sustained phosphorylation of platelet p38 mitogen-activated protein kinase (p38 MAPK). The effect was time- and dose-dependent. The HCy effect on p38 MAPK phosphorylation was prevented by N-acetyl-L-cysteine and iloprost and was partially inhibited by nordihydroguaiaretic acid. Moreover, the incubation of platelets with HCy led to the phosphorylation of cytosolic phospholipase A2 (cPLA2). In addition HCy promoted cPLA2 activation, assessed as arachidonic acid release. The cPLA2 phosphorylation and activation were both impaired by the inhibition of p38 MAPK through SB203580. This effect was not complete, reaching at the most the 50% of the total. In FURA 2-loaded platelets, HCy induced a dose-dependent intracellular calcium rise suggesting that the calcium elevation promoted by HCy could participate in the cPLA2 activation, leading to arachidonic acid release and TXB2 formation. In conclusion, our data provide insight into the mechanisms of platelet activation induced by HCy, suggesting that the p38 MAPK/cPLA2 pathway could play a relevant role in platelet hyperactivity described in hyperhomocysteinemia.

Antigens, Human Platelet↗

PubMed2005

Metabolic syndrome is associated with early signs of organ damage in nondiabetic, hypertensive patients.

OBJECTIVES: Hypertensive patients with metabolic syndrome (MS) are at greater risk for cardiovascular disease. To get a better understanding of the pathophysiology underlying this association, we evaluated the relationship between MS and subclinical organ damage in essential hypertensive patients. DESIGN AND SETTING: A total of 354 untreated, nondiabetic patients with primary hypertension were included in the study. A modified ATP III definition for MS was used, with body mass index replacing waist circumference. Albuminuria was measured as albumin to creatinine ratio, left ventricular mass index (LVMI) was assessed by echocardiography and carotid abnormalities by ultrasonography. RESULTS: The prevalence of MS was 25%. Patients with MS were more likely to be smokers (P = 0.004) and had higher serum uric acid levels (P = 0.004). Moreover, they showed higher urinary albumin excretion (P = 0.0004) and LVMI (P = 0.0006), increased intima-media thickness (P = 0.045), as well as higher prevalence of microalbuminuria (P = 0.03) and left ventricular hypertrophy (LVH; P = 0.003). After adjusting for age, gender and duration of hypertension, we found that the presence of MS entails a twofold greater risk for microalbuminuria (P = 0.04), LVH (P = 0.003) and carotid abnormalities (P < 0.05). When patients were stratified according to the number of components of MS, albuminuria (P = 0.002) and LVMI (P = 0.005) increased progressively across categories. CONCLUSIONS: Metabolic syndrome is associated with subclinical organ damage in nondiabetic, essential hypertensive patients. These data may, in part, explain the high cardiovascular morbidity and mortality that is observed in hypertensive patients with MS.

Albuminuria↗

PubMed2004

Creatinine clearance and signs of end-organ damage in primary hypertension.

A reduction in renal function is associated with high cardiovascular morbidity and mortality in hypertension. The aim of the present study was to investigate the relationship between creatinine clearance and subclinical organ damage in 957 never previously treated, middle-aged patients with primary hypertension. Renal function was estimated by means of the serum creatinine level using the Cockcroft-Gault formula; left ventricular hypertrophy (LVH) was determined according to electrocardiographic criteria; and retinal vascular changes were evaluated by direct ophthalmoscopy. Creatinine clearance was, on the average, 83+/-21.2 ml/min, and the prevalence of LVH and retinopathy was 13 and 49%, respectively. Creatinine clearance was inversely related to the duration of disease (r=-0.132, P<0.0001), systolic blood pressure (r=-0.110, P=0.001), serum glucose (r=-0.090, P=0.007), total cholesterol (r=-0.196, P<0.0001), and LDL-cholesterol (r=-0.196, P<0.0001). Patients in the lower quintile of creatinine clearance showed a higher prevalence of electrocardiogram (ECG) determined LVH (P=0.04), as well as retinal changes (P=0.02). The risk of having LVH or retinal vascular changes increases significantly with each s.d. decrease in creatinine clearance, regardless of traditional cardiovascular risk factors. Moreover, patients with ECG-determined LVH and retinal changes showed lower creatinine clearance as compared to those with lesser degrees of target organ involvement (P<0.01). In conclusion, a mild reduction in creatinine clearance is associated with preclinical end-organ damage in patients with normal creatinine and primary hypertension. These data may help explain the high cardiovascular mortality observed in patients with renal dysfunction. Routine evaluation of creatinine clearance could be useful for identifying patients at higher cardiovascular risk.

Adult↗

PubMed2003

Effects of homocysteine on l-arginine transport and nitric oxide formation in human platelets.

BACKGROUND: Recent evidence indicates that hyperhomocysteinaemia is an independent risk factor for atherosclerosis, thrombosis and other cardiovascular diseases. This may be secondary to impaired fibrinolysis or increased platelet reactivity. Nitric oxide (NO), a product from l-arginine by NOS and potent antiaggregating agent, plays an important role in the regulation of platelet function. DESIGN: The present study aimed to define the effect of homocysteine on the l-arginine/NO pathway in human platelets. l-Arginine uptake, NO formation and Ca2+ levels were measured. Moreover the homocysteine effect on platelet activation induced by thrombin was tested. RESULTS: Homocysteine causes a concentration-dependent inhibition of l-arginine transport. Results show that homocysteine does not modify the Km parameter, but it significantly decreases the Vmax value. The nitrite and nitrate formation, strictly correlated with the l-arginine transport, also significantly decreased. In contrast, cNOS activity remained unchanged upon homocysteine treatment. In addition homocysteine in a dose dependent manner increased the intracellular Ca2+ concentration and platelet response to thrombin. CONCLUSIONS: Results indicate that the l-arginine/NO pathway is one of the various targets of homocysteine in human platelets. The increased Ca2+ levels associated with reduced NO formation may generate hyperactivation and may contribute to the thrombogenic processes.

Arginine↗

PubMed2002

Microalbuminuria is an integrated marker of subclinical organ damage in primary hypertension.

Increased urine albumin excretion is associated with an unfavourable cardiovascular risk profile and prognosis in primary hypertension, even though its pathogenesis is currently unknown. Microalbuminuria (Mi) has been proposed as an integrated marker to identify patients with subclinical organ damage, but its routine use is still too often neglected in clinical practice. The aim of our study was to evaluate the relationship between urinary albumin excretion and early signs of subclinical target organ damage (TOD), namely left ventricular hypertrophy and carotid atherosclerosis in a large group of non diabetic hypertensive patients. A group of 346 never treated patients with primary hypertension (212 men, 134 women, mean age 47 +/- 9 years) referred to our clinic were included in the study. They underwent the following procedures: (1) family and personal medical history and physical examination; (2) clinical blood pressure measurement; (3) routine blood chemistry and urine analysis including determination of urinary albumin excretion (ACR); (4) electrocardiogram; (5) ultrasound evaluation of left ventricular mass (LVMI) and carotid artery thickness (IMT). The overall prevalence of Mi, left ventricular hypertrophy, and carotid plaque was 13, 51, and 24% respectively. Mi was significantly correlated with LVMI (P < 0.0001), IMT (P < 0.0001) and several metabolic and non-metabolic risk factors (blood pressure, body mass index, serum lipids). Cluster analysis identified three subgroups of patients who differ significantly with regards to TOD and albuminuria (P < or = 0.001 for each of the examined variables). Patients with higher IMT and LVMI values also showed increased ACR levels. Furthermore, patients with microalbuminuria were more likely to have both LVH and IMT values above the median for the study population (OR 21, C.I. 4.6-99.97, P < 0.0001). Mi is an integrated marker of subclinical organ damage in patients with primary hypertension. Evaluation of urinary albumin excretion is a specific, cost-effective way to identify patients at higher risk for whom additional preventive and therapeutic measures are advisable.

Albuminuria↗

PubMed2002

Effect of homocysteine on arachidonic acid release in human platelets.

BACKGROUND: It has been suggested that homocysteine is implicated in the risk of atherosclerosis and thrombosis. The pathogenic mechanism has not been clarified, but oxygen-free species produced by the homocysteine metabolism and auto-oxidation could have a role. DESIGN: We have studied the effect of homocysteine on arachidonic acid release in human platelets. Two important products of arachidonic acid metabolism - thromboxane B2 (TXB2) and reactive oxygen species (ROS) - have been assayed. RESULTS: Results indicate that homocysteine induces arachidonic acid release that is partially inhibited by 5,8,11,14-eicosatetraynoic acid (ETYA). Platelet incubation with homocysteine significantly increases basal levels of TXB2 and ROS. The effect is time- and dose-dependent. The TXB2 formation is strictly correlated with the arachidonic acid release. Moreover, ROS accumulation is largely inhibited by ETYA and partially reduced by diphenyleneiodonium (DPI), suggesting the involvement both of enzymes metabolising arachidonic acid (cyclooxygenase, lipooxygenase, cytochrome P450 monooxygenase) and of NAD(P)H oxidase. CONCLUSION: Homocysteine induces oxidative stress in human platelets in vitro. The unbalance in platelet redox-state and the increased TXB2 formation may generate hyperactivation, contributing to a thrombogenic state leading to cardiovascular diseases.

5,8,11,14-Eicosatetraynoic Acid↗

PubMed2001

5,10-Methylenetetrahydrofolate reductase polymorphism and early organ damage in primary hypertension.

Hyperhomocyst(e)inemia is a known risk factor for the development of atherosclerotic vascular damage. Plasma homocyst(e)ine levels are influenced by nutritional and hereditary factors. A point mutation (cytosine to thymidine substitution; C677T) in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) makes the enzyme thermolabile and has been associated with elevated homocyst(e)ine levels in homozygous carriers (TT genotypes). We evaluated the relationship between the T allele encoding for the thermolabile variant of MTHFR and several biochemical risk factors and early signs of hypertensive and atherosclerotic organ damage in 206 untreated patients with primary hypertension. The MTHFR genotype was evaluated by polymerase chain reaction. Albuminuria was measured as albumin-to-creatinine ratio in three nonconsecutive first morning urine samples (negative urine culture). Persistent Mi (Alb+) was defined as an average albumin-to-creatinine ratio between 2.38 and 19 (men) and 2.96 and 20 (women). Left ventricular (LV) mass index (LVMI) was assessed by M-B mode echocardiography (LV hypertrophy, LVH = LVMI > or = 125 g/m2), carotid geometry by high-resolution ultrasound scan, and retinal vascular changes by direct ophthalmoscopy (Keith-Wagener classification). The prevalence of Mi, LVH, and retinopathy was 14%, 45%, and 42%, respectively. The prevalence of carotid plaque was 25%. Allele frequencies for C (wild-type allele) and T allele (mutant allele) were 56% and 44%, respectively. Genotype frequencies were CC 29%, CT 54%, TT 17% according to Hardy Weinberg equilibrium. There were no differences as for age, sex, body mass index, blood pressure levels, lipid profile, smoking habits, and alcohol intake, and LVMI and urinary albumin excretion on the basis of MTHFR genotype. Patients with TT polymorphism showed a higher prevalence of retinal vascular changes (TT, 61% v CT + CC, 38%; P < .02) and carotid plaque (TT, 42% v CT + CC, 21%; P < .05) compared to patients with CC and CT polymorphism. Moreover, patients with T allele showed increased carotid artery size as demonstrated by intima plus media thickness (IT, 0.79 +/- 0.05 mm v CT + CC, 0.67 +/- 0.02 mm; P < .02), relative wall thickness (TT, 0.23 +/- 0.01 mm v CT + CC, 0.20 +/- 0.005 mm; P < .02), and surface area (TT, 19 +/- 1.9 mm2 v CT + CC, 15 +/- 0.55 mm2; P < .05). Multiple linear regression analysis demonstrated that MTHFR genotype and systolic blood pressure independently influence intima-media thickness and together account for about 11% of its variations (r2 = 0.11, F = 9.7, dF = 1-205, P < .0001). Homozygosity for the T allele of the MTHFR gene is an independent risk factor for the development of early atherosclerotic organ damage in hypertensive patients.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗

PubMed2001

Impaired L-arginine uptake in platelets from type-2 diabetic patients.

The L-arginine uptake of resting platelets from type-2 diabetic patients and control subjects was measured and the kinetic parameters defined. The effect of platelet stimulation with agonists was also investigated. Kinetic studies showed that the K(m) value for L-arginine transport was not different in patients compared with control subjects, while V(max) was significantly decreased in patients compared with controls. Moreover, agonists able to mobilize Ca(2+) produced a further decrease in the L-arginine uptake in controls and in patients, suggesting that Ca(2+) intracellular levels down-regulate L-arginine transport in platelets from both control subjects and patients. Data suggest that drugs designed to control intracellular Ca(2+) might restore platelet function in diabetic patients.

Aged↗

PubMed2000

Synthesis, antiplatelet activity and comparative molecular field analysis of substituted 2-amino-4H-pyrido[1,2-a]pyrimidin-4-ones, their congeners and isosteric analogues.

2-(1-Piperazinyl)-4H-pyrido[1,2-a]pyrimidin-4-one (5a) is a recently described in vitro inhibitor of human platelet aggregation which specifically inhibits the activity of high affinity cAMP phosphodiesterase. A number of substitution derivatives, isosteres, and analogues of 5a were now synthesized and tested in vitro for their inhibitory activity on human platelet aggregation induced in platelet-rich plasma by ADP, collagen, or the Ca2+ ionophore A23187. Among the most effective compounds, the 6-methyl, 8-methyl and 6,8-dimethyl derivatives of 5a resulted nearly as active as the lead when platelet aggregation was induced by ADP or A23187, but less active when collagen was the inducer. On the basis of present results and those previously obtained by us in this and 2-aminochromone structural fields, we have developed a statistically significant 3-D QSAR model, using comparative molecular field analysis (CoMFA), describing the variation of the antiplatelet activity in terms of molecular steric and electrostatic potential changes.

Humans↗

PubMed2000

Genetic polymorphism of the renin-angiotensin system and organ damage in essential hypertension.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) plays a significant role in the development of hypertensive cardiac and vascular remodeling. Recently, several genetic variants of its key components, which may be clinically relevant and thus prove to be useful in the evaluation of cardiovascular risk, have been described. We therefore investigated the association between ACE I/D, AGT M235T, and AT1 A1266C gene polymorphisms and early signs of target organ damage in 215 untreated patients with essential hypertension (EH). METHODS: Genotyping was based on the polymerase chain reaction technique, with further restriction analysis when required. Albuminuria was measured as the albumin-to-creatinine ratio (ACR). The left ventricular mass index (LVMI) was assessed by echocardiography (LVH = LVMI > or = 125 g/m2), carotid wall thickness (IMT) by an ultrasonographic (US) scan, and retinal vascular changes by direct ophthalmoscopy (Keith-Wagener classification). RESULTS: The prevalence of microalbuminuria (Mi), LVH, and retinal vascular changes was 14, 46, and 74%, respectively. ACE, AGT, and AT1 genotype distribution was in agreement with the Hardy-Weinberg equilibrium. There was no difference in age, duration of disease, body mass index (BMI), blood pressure, and lipid profile when data were analyzed on the basis of genotype. Serum levels of angiotensin-converting enzyme (ACE) were related to the ACE genotype (10.2 +/- 0.5, DD; 8.2 +/- 0.3, ID; 6.5 +/- 0.4 IU/mL, II; P < 0. 0001 by analysis of variance). The ACE genotype independently influences serum ACE levels and accounts for approximately 14% of its variations (F = 26.7, r2 = 0.1393, df 1 to 214, P < 0.0001). Patients with DD and ID genotypes showed higher levels of ACR (1.59 +/- 0.2, DD + ID; 0.8 +/- 0.2 mg/mmol, II; P < 0.006 by ANOVA) and bigger LVMI (124.1 +/- 2.3, DD + ID vs. 117.8 +/- 3.6 g/m2, II; P < 0.01 by ANOVA). No differences in the prevalence and degree of target organ damage (TOD) were found when data were analyzed on the basis of the AGT and AT1 genotypes, respectively. Potentially unfavorable combinations of genotypes were also investigated by K-means cluster analysis. Two subgroups of patients were identified (cluster 1, N = 70; cluster 2, N = 57), and each differed significantly with regards to the presence and degree of TOD and patterns of RAAS gene polymorphisms (F, 15.97 for ACR; F, 7.19 for IMT; F, 217.03 for LVMI; F, 3.91 for ACE; F, 4.06 for AGT; and F, 5. 22 for AT1; df 1 to 214, P < 0.02, for each one of the variables examined). CONCLUSION: The D allele of the ACE gene may be an independent risk factor for the development of target organ damage, and evaluating it could be useful for assessing cardiovascular risk in EH. Unfavorable patterns of RAAS genotypes seem to predispose patients to subclinical cardiovascular disease in EH.

Adolescent↗

PubMed1999

Regulation of L-arginine uptake by Ca(2+) in human platelets.

L-Arginine uptake and Ca(2+) changes in unstirred platelets activated by thrombin, collagen and Ca(2+) ionophore A23187 were evaluated. Thrombin did not affect L-arginine uptake at short incubation times (2-15 min), but at prolonged times slowed down the amino acid transport. Collagen was ineffective. A23187 decreased the L-arginine uptake in a dose-dependent manner, producing the maximal inhibition at 5 microM. In FURA 2-loaded platelets collagen did not modify Ca(2+) basal level, thrombin induced a late Ca(2+) rise and A23187 dose-dependently increased cytosolic Ca(2+), eliciting the highest increase at 5 microM. It is likely that L-arginine uptake is inversely modulated by Ca(2+) concentrations and is inhibited during platelet stimulation with agonists which induce cytosolic Ca(2+) elevation.

Arginine↗

PubMed1999

N-ethylmaleimide inhibition of thrombin-induced platelet aggregation.

The data presented in this report show that N-ethylmaleimide (NEM) is a powerful inhibitor of thrombin-induced platelet aggregation. NEM increased guanosine 3', 5'-cyclic monophosphate (cGMP) and adenosine 3', 5'-cyclic monophosphate (cAMP) levels in intact cells. The inhibition of cAMP high-affinity phosphodiesterase and cGMP phosphodiesterase was implicated in the elevation of the cyclic nucleotides. NEM dose dependently blocked the thrombin-stimulated, but not the phorbol myristate acetate-dependent phosphorylation of the protein kinase C substrate pleckstrin. Myosin light chain phosphorylation was also inhibited by NEM. In addition, the sulphydryl reagent inhibited Ca2+ mobilisation induced by thrombin. The data indicate that phospholipase C activation by thrombin is interrupted by NEM at the level of receptor-mediated signal transduction.

Blood Proteins↗

PubMed1999

N-ethylmaleimide-stimulated arachidonic acid release in human platelets.

Treatment of human platelets with the alkylating agent N-ethylmaleimide (NEM) induces arachidonic acid release. The effect was time- and dose-dependent. NEM-stimulated arachidonic acid mobilisation could be prevented by pretreating platelets with the cytosolic phospholipase A2 (cPLA2)-specific inhibitor arachidonyltrifluoromethyl ketone. Moreover, the tyrosine kinase inhibitor genistein was able to significantly inhibit arachidonic acid mobilisation. NEM-stimulated release of arachidonic acid appears to be a Ca2+-dependent mechanism, as shown by the observation that arachidonic acid mobilisation was significantly reduced by platelet treatment with EGTA and abolished by preloading platelets with the intracellular chelator 1,2-bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetra (acetoxymethyl) ester (BAPTA/AM). In Fura-2-loaded platelets, NEM was able to significantly increase the intracellular Ca2+ level. The Ca2+ elevation was significantly reduced in the presence of EGTA and suppressed by cell treatment with BAPTA/AM. Arachidonic acid released by NEM produced a significant increase in reactive oxygen species (ROS) intracellular levels, which was partially inhibited by diphenyleneiodonium and almost completely suppressed by 5,8,11,14-eicosatetraynoic acid. In conclusion, the results in this study demonstrate that NEM stimulates arachidonic acid release by cPLA2 activation through intracellular Ca2+ elevation. In addition, tyrosine specific protein kinases seem to be involved in arachidonic acid release. ROS was also shown to be formed during arachidonic acid metabolisation.

5,8,11,14-Eicosatetraynoic Acid↗

PubMed1999

Increased renal resistive index in patients with essential hypertension: a marker of target organ damage.

BACKGROUND: Increased renal resistance detected by ultrasound (US) Doppler has been reported in severe essential hypertension (EH) and recently was shown to correlate with the degree of renal impairment in hypertensive patients with chronic renal failure. However, the pathophysiological significance of this finding is still controversial. METHODS: In a group of 211 untreated patients with EH, we evaluated renal resistive index (RI) by US Doppler of interlobar arteries and early signs of target organ damage (TOD). Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. Left ventricular mass was evaluated by M-B mode echocardiography, and carotid wall thickness (IMT) by high resolution US scan. RESULTS: RI was positively correlated with age (r=0.25, P=0.003) and systolic blood pressure (SBP) (r=0.2, P=0.02) and with signs of early TOD, namely ACR (r=0.22, P=0.01) and IMT (r=0.17, P<0.05), and inversely correlated with renal volume (r=-0.22, P=0.01) and diastolic blood pressure (r=-0.23, P=0.006). Multiple linear regression analysis demonstrated that age, gender, ACR and SBP independently influence RI and together account for approximately 20% of its variations (F=8.153, P<0.0001). When clinical data were analysed according to the degree of RI, the patients in the top quartile were found to be older (P<0.05) and with higher SBP (P<0.05) as well as early signs of TOD, namely increased ACR (P<0.002) and IMT (P<0.005 by ANOVA), despite similar body mass index, uric acid, fasting blood glucose, lipid profile and duration of hypertension. Furthermore, patients with higher RI showed a significantly higher prevalence of microalbuminuria (13 vs 12 vs 3 vs 33% chi2=11.72, P=0.008) and left ventricular hypertrophy (40 vs 43 vs 32 vs 60%, chi2=9.25, P<0.05). CONCLUSIONS: Increased RI is associated with early signs of TOD in EH and could be a marker of intrarenal atherosclerosis.

Adult↗

PubMed1999

Left ventricular geometry and function in patients with essential hypertension and microalbuminuria.

BACKGROUND: Microalbuminuria has recently emerged as a strong, independent predictor of cardiovascular mortality in patients with essential hypertension, yet the pathophysiological mechanisms underlying this association remain to be elucidated. OBJECTIVE: To study the relationship between microalbuminuria and left ventricular geometry and function and extra-cardiac vascular changes in a group of 211 untreated hypertensive patients. METHODS: Albuminuria was evaluated as albumin-to-creatinine ratio in three non-consecutive first morning urine samples. Left ventricular mass index and function were assessed by M-B mode echocardiography and carotid wall thickness by high-resolution ultrasound scan. RESULTS: The prevalences of microalbuminuria and left ventricular hypertrophy were 14 and 47% respectively. Patients in the top quartile of albuminuria showed a higher left ventricular mass index (57 +/- 1.8, 55 +/- 2, 47 +/- 1.4 and 48 +/- 1.6 g/m2.7, respectively; P< 0.0001) as well as a higher prevalence of left ventricular hypertrophy (72, 65, 26 and 25%, respectively; P< 0.001) and especially concentric hypertrophy (56, 47, 17 and 21%, respectively; P< 0.0001) in the four quartiles of albuminuria. Microalbuminuric patients showed depressed left ventricular performance as indicated by a reduced midwall fractional shortening (15.7 +/- 0.3, 15.9 +/- 0.3, 16.7 +/- 0.4 and 16.8 +/- 0.3%, respectively; P< 0.02). Furthermore patients in the top quartile of albuminuria showed increased carotid wall thickness as compared to normoalbuminuric patients (0.78 +/- 0.03, 0.7 +/- 0.04, 0.65 +/- 0.03 and 0.6 +/- 0.03 mm, respectively; P < 0.001). CONCLUSIONS: Hypertensive patients with microalbuminuria show a higher prevalence of unfavourable left ventricular geometric patterns, depressed left ventricular function and early signs of extra-cardiac vascular damage. These findings strengthen the role of microalbuminuria as an indicator of subclinical cardiovascular disease and may account for the worse outcome that is usually associated with increased urinary albumin excretion in essential hypertension.

Adult↗

PubMed1999

Are Angiotensin Converting Enzyme and von Willebrand factor circulating levels useful surrogate parameters to monitor disease activity in Kawasaki disease?

To verify if Angiotensin Converting Enzyme (ACE) and von Willebrand factor (vWF) may be used as a laboratory marker for the follow-up of endothelial derangement and therapeutic efficacy in Kawasaki disease (KD), circulating ACE, vWF routine hematological tests and cardiac involvement were assessed in 32 children with established diagnosis of KD before and up to six months after intravenous gamma-globulins (i.v.IG) treatment. I.v.IG treatment normalized progressively all the hematological parameters to levels comparable with healthy controls within 30 days. At baseline, ACE levels resulted significantly lower (1.8 +/- 1.3 pmol/ml/min), and vWF levels significantly increased (210.3 +/- 35.2%) when compared with controls (respectively 7.0 +/- 0.9 pm/ml/min and 99 +/- 17.9%). Seven days after the treatment vWF levels were decreased (188 +/- 18.4%) but still significantly higher than controls, and fully normalized after 15 days (104.8 +/- 14.3%). ACE levels were found progressively increased at 7, 15, and 30 days after the treatment (respectively 2.7 +/- 1.0, 3.7 +/- 0.4, 5.04 +/- 0.9 pm/ml/min) and reached the range of normality only after two months (7.74 +/- 2.46 pm/ml/min). The present study shows that ACE and vWF circulating levels are significantly modified during the acute phase of the disease.

Child, Preschool↗

PubMed1999

[Complications of Barrett's esophagus: indications for esophageal resection with special reference to high-grade dysplasia].

BACKGROUND: Columnar lined oesophagus (Barrett's oesophagus) can sometimes be associated with complications such as stricture, ulcer and dysplasia. In some selected cases there is an indication for oesophageal resection. METHODS: From 1983 to 1997, 12 patients underwent oesophagectomy for "complicated" Barrett's oesophagus. All patients had gastroesophageal reflux and Barrett metaplasia for many years. Ten of them were symptomatic, and pH-manometric alterations as well as alterations were noted at biliary scintigraphy. Ten patients had intestinal metaplasia. Two patients had previous antireflux operations. Four had a long (3-5 cm) and undilatable stricture. One was affected by a perforating ulcer. One patient had an indefinite grade dysplasia but endosonography revealed high suspicion of cancer. Six patients had a high-grade dysplasia. Operative technique consisted of a transhiatal oesophagectomy in nine cases and a laparotomic and right thoracotomic oesophagectomy (Ivor-Lewis) in two. RESULTS: There was no 30-day mortality; three post operative complications were observed. One of the four patients suffering from stricture died four years after intervention due to non-related causes; the other three are still living and regularly feed per os after 12, 9 and 7 years. The patient with ulcer is still living after 6 years and regularly feeding per os. The patient suffering from an indefinite grade dysplasia had an adenocarcinoma (stage IIa) on the operative specimen. The patient is still living after 2 years. Three patients operated for high-grade dysplasia had an adenocarcinoma on the specimen. Two patients (stage I) are living after 3 and 5 years. One patient (stage IIa) died after 19 months with recurrence. CONCLUSIONS: In case of non neoplastic "complicated" Barrett's oesophagus the indication for the oesophageal resection can be considered as the extreme useful therapy only after an accurate selection of patients. Especially in case of high-grade dysplasia, the great incidence of unexpected adenocarcinoma indicates oesophagectomy for patients who are suitable for surgery.

Aged↗