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Biomedical subjects

M Mercuri

Publications and source records attributed to M Mercuri.

At least 19 recordsLinked to original sources
PubMed1995

Inverse relationship between cardiorespiratory fitness and carotid atherosclerosis.

The association between cardiorespiratory fitness (VO2max) and carotid atherosclerosis was analyzed in 163 men, aged 50 to 60 years. VO2max was assessed using breath-by-breath respiratory gas analyses during maximal exercise stress test. Atherosclerosis was evaluated quantitatively as intima-media thickness (IMT) of the right and left carotid arteries by high-resolution B-mode ultrasonography. Mean VO2max was 29.6 ml/kg per min (95%CI 28.7;30.5), common carotid IMT 1.04 mm (95%CI 1.01;1.07) and carotid bifurcation IMT 1.73 mm (95%CI 1.66;1.81). VO2max correlated inversely with carotid bifurcation IMT (r = -0.31, P < 0.001), but not with common carotid IMT (r = -0.13, P = 0.102). Men in the highest quartile of VO2max had lower (P < 0.001) bifurcation IMT 1.51 mm (95%CI 1.41;1.61) than men in the lowest (1.95 mm (95%CI 1.75;2.16)) and in the second lowest VO2max quartile (1.79 mm (1.63; 1.95)). The difference persisted (P = 0.014) after controlling for age, LDL-cholesterol, systolic blood pressure, saturated fat intake, current health status and exercise-induced ST-segment depression. These data suggest that cardiorespiratory fitness is an important independent predictor of carotid atherosclerosis in middle-aged men.

Arteriosclerosis↗
PubMed1995

Dedifferentiated chondrosarcoma.

We reviewed 74 cases of dedifferentiated central and peripheral chondrosarcoma. Histologically these tumours consist of an underlying cartilaginous component (either benign or malignant) juxtaposed to a high-grade non-cartilaginous component, with a typically abrupt transition between the two tissue types. The non-cartilaginous component may constitute a very small or a very large proportion of the tumour, so diagnosis often requires histological evaluation of the entire tumour. The diagnosis is often suspected on the basis of the clinical course and careful evaluation of the radiographic characteristics. Central dedifferentiated chondrosarcoma can be classified radiographically into three types. In type I (36 cases in our review) the radiographic features are the same as those of a central chondrosarcoma, with the addition of a region with very aggressive radiographic features. Type 2 lesions (20 cases) resemble the underlying benign enchondroma but also have destructive changes and/or a large soft tissue mass. Type 3 lesions (8 cases) are not distinctive radiographically and present as a very high grade destructive lesion of bone. These cases are diagnosed following biopsy or tumour resection. The prognosis of these tumours is extremely poor, with 13% overall 5-year survival in this series. Improved survival was found in those cases where diagnosis was prompt and surgical treatment with a wide or radical margin was attained. No benefit was found from the use of adjuvant chemotherapy or radiotherapy. Thus, early recognition of the characteristic radiographic features, adequate histological sampling, and wide or radical surgical margins are necessary for satisfactory management of this highly malignant variant of chondrosarcoma.

Adult↗
PubMed1995

Ultrasonographic correlates of carotid atherosclerosis in transient ischemic attack and stroke.

BACKGROUND AND PURPOSE: Atherosclerotic plaques in extracranial carotid arteries, particularly in the bifurcation of the common carotid and internal carotid arteries, may cause transient cerebral ischemia and stroke by lumen stenosis or plaque-related thromboembolism. B-mode ultrasound imaging has the capability of providing information on plaque thickness, characteristics, and location in carotid arteries. METHODS: A retrospective analysis of 242 stroke and 336 transient ischemic attack (TIA) patients, recruited for the B-Scan Ultrasound Imaging Assessment Program, was performed to determine the ultrasonographic correlates of carotid atherosclerosis and acute cerebral ischemia. A matched case-control study design was used to compare brain hemispheres with ischemic lesions ("cases") to unaffected contralateral hemispheres ("controls") with regard to the presence and characteristics of carotid artery plaques. RESULTS: The first set of analyses examined the association between the presence of carotid plaques ipsilateral to the brain lesion and the occurrence of stroke or TIA and showed an association with recent episodes of TIA and stroke (odds ratio [OR], 1.6; P = .03) but not with past episodes. In a subset (n = 232) of patients with plaques in both carotid arteries and recent cerebral ischemic events, stroke was associated with ipsilateral carotid artery occlusion (P = .02). Lumen measurements at the site of the minimum residual lumen (MRL) diameter showed a significant association between a narrower lumen diameter in the carotid artery ipsilateral to case hemisphere and stroke (difference, 1.0 mm; P = .0003). TIA patients showed an association between both hypoechoic carotid plaques (OR, 3.0; P = .005) and the presence of longitudinal lesion motion (OR, 3.0; P = .02) with ipsilateral brain involvement. Plaque thickness at the MRL was positively correlated with both ipsilateral TIA (ipsilateral side, 4.4 +/- 0.15 mm; contralateral side, 3.9 +/- 0.16 mm; P = .007) and stroke (ipsilateral side, 4.2 +/- 0.23 mm; contralateral side, 3.3 +/- 0.21 mm; P = .0006). CONCLUSIONS: These data demonstrate significant relationships between carotid artery ultrasound plaque characteristics and ischemic cerebrovascular events. These findings encourage further prospective studies in asymptomatic subjects focused on echographic carotid plaque characteristics as predictors of subsequent TIA or stroke.

Aged↗
PubMed1995

Quantitative ultrasonographic evaluation of the carotid arteries in hypertension.

Current treatment goals for hypertension include the prevention of end-organ injuries. Hypertension is certainly among the major contributors to atherogenesis, and many antihypertensive drugs seem to have wall-protecting properties. It is critical to identify, test, and implement non-invasive methods for the screening of the population in order to detect early wall abnormalities and to monitor the long-term effects of different antihypertensive treatments. Among these methods, B-mode ultrasound examination of carotid arteries has shown great potential in evaluating treatments that may prevent hypertension-related wall injuries.

Antihypertensive Agents↗
PubMed1994

Noninvasive imaging protocols to detect and monitor carotid atherosclerosis progression.

It has been shown that B-mode ultrasound imaging is a valid and reliable technique to measure arterial wall thickness. Based on the results of early validation studies and relatively small-scale investigations, large-scale epidemiologic studies using high-resolution ultrasonography were designed to provide information on the association of wall thickness and cardiovascular risk factors, and to determine the prevalence, extent, and severity of peripheral atherosclerosis. Recent reports indicate that ultrasonographic endpoints correlate with the most important cardiovascular risk factors. Furthermore, noninvasive carotid endpoints have been shown to be predictive of clinical atherosclerosis status with a high degree of confidence. B-mode ultrasonography has also been used to evaluate prospectively the natural history of peripheral atherosclerosis by monitoring lesion growth over time. Recently, ultrasonographic measurements of the arterial wall have been chosen as the primary and secondary endpoints for several clinical trials of the antiatherogenic effects of behavioral and pharmacologic interventions on major cardiovascular risk factors such as hypercholesterolemia and hypertension.

Angiography↗
PubMed1994

Association of risk factors and body iron status to carotid atherosclerosis in middle-aged eastern Finnish men.

High body iron stores have been proposed as a risk factor for advanced atherosclerosis. We investigated the prevalence of early atherosclerotic changes, and their relation to conventional CHD risk factors and body iron status. A cross-sectional study was carried out in 206 men aged 50 to 60 years (6% random population sample). Intima-media thickness (IMT) of the carotid artery was evaluated with high-resolution B-mode ultrasonography. Statistical analyses were performed separately for men with and without cardiovascular disease (CVD). Among all the study participants, 6.6% had IMT > 1.3 mm in the common carotid artery, whereas 53.8% had IMT > 1.5 mm in the carotid bifurcation. Respective values were 4.8% and 46.8% for those without CVD, and 8.5% and 62.2% for those with CVD. Mean IMT in the carotid bifurcation, the predilection site for atherosclerosis, was 1.85 mm (95% CI 1.72; 1.98) in the men with CVD, as compared to 1.65 mm (95% CI 1.56; 1.73) in the men free of CVD. Serum LDL cholesterol (beta = 0.26), saturated fat intake (beta = 0.20), blood haemoglobin (beta = -0.29), systolic blood pressure (beta = 0.21) and smoking (beta = 0.19), jointly explained 23% of the variance in the carotid bifurcation IMT in the men without CVD. Neither serum ferritin, transferrin nor dietary iron levels were associated with carotid bifurcation atherosclerosis. On the other hand, in the men with CVD, age (beta = 0.34) and physical activity (beta = -0.25) jointly explained 16.5% of the IMT variance in the carotid bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Stenosis↗
PubMed1994

Premature carotid atherosclerosis: does it occur in both familial hypercholesterolemia and homocystinuria? Ultrasound assessment of arterial intima-media thickness and blood flow velocity.

BACKGROUND AND PURPOSE: Homocystinuria due to cystathionine beta-synthase deficiency and familial hypercholesterolemia are inherited disorders of metabolism that are associated with premature development of cardiovascular disease. This study addresses the possibility that different patterns of carotid wall damage and cerebral blood flow hemodynamics are present in these two metabolic diseases. METHODS: Twelve patients with homocystinuria due to cystathionine beta-synthase deficiency (mean age, 24 years), 10 patients with homozygous familial hypercholesterolemia (mean age, 26 years), and 11 healthy control subjects (mean age, 26 years) underwent a vascular examination by noninvasive methods. B-mode ultrasound imaging was used to obtain measurements of intima-media thickness of common carotid, bifurcation, and internal carotid arteries as an index of atherosclerosis. Cerebral blood flow velocity was estimated from vascular examination of the middle cerebral artery by transcranial Doppler. Systolic, diastolic, and mean velocities were measured. Pulsatility index, a possible indicator of vascular resistance in the cerebral circulation, was also calculated. RESULTS: Mean maximum intima-media thickness was 1.4 mm in patients with familial hypercholesterolemia, 0.6 mm in patients with homocystinuria, and 0.6 mm in control subjects. The difference between hypercholesterolemic and homocystinuric patients or control subjects was statistically significant (P < .001). Diastolic blood flow velocities were significantly reduced in the middle cerebral arteries of hypercholesterolemic patients compared with homocystinuric patients or control subjects (P < .05), whereas systolic or mean velocities did not differ. The pulsatility index, a possible indicator of vascular resistance in the cerebral circulation, was significantly higher in hypercholesterolemic patients compared with homocystinuric patients or healthy control subjects (P < .01). A direct relation was demonstrated between pulsatility index of the middle cerebral artery and mean maximum intima-media thickness of carotid arteries on the same side (P < .001). CONCLUSIONS: Familial hypercholesterolemia is responsible for diffuse and focal thickening of carotid arteries and possibly also for hyperlipidemic endothelial dysfunction extending to small resistance arteries and leading to a disturbed cerebral blood flow. Patients with homocystinuria due to homozygosis for cystathionine beta-synthase deficiency seldom have plaques in their carotid arteries. They are similar to healthy control subjects with regard to both intima-media thickness and blood flow velocity in the middle cerebral artery. Therefore, it is unlikely that typical atherosclerotic lesions precede thrombotic events in homocystinuria. However, it is possible that arterial dilatations caused by medial damage lead to thrombosis in homocystinuric patients.

Adolescent↗
PubMed1994

Ankle resection arthrodesis in patients with bone tumors.

The authors report 12 cases of bone tumors localized in the distal tibia treated by resection and reconstruction with ankle arthrodesis, using bone grafts and fixation with Kuntscher or Grosse-Kempf nail or plate. In seven cases autografts were used, and in five cases autografts combined with allografts were used. In three of these five patients, a vascularized fibula combined with a "gutter-like" allograft was used to reconstruct the bone defect. In all cases, the functional and oncologic results were good and all patients were disease free at an average follow-up of 68 months.

Adolescent↗
PubMed1994

Apolipoprotein(a), fibrinopeptide A and carotid atherosclerosis in middle-aged men.

The association between apolipoprotein(a) [apo(a)], fibrinogen, fibrinopeptide A (FPA) and carotid intima-media thickness (IMT) was analyzed in Eastern Finnish men aged 50 to 60 years. Apo(a) correlated directly with carotid bifurcation (r = 0.26, p = 0.001), but not with common carotid IMT. Men in the lowest quartile of apo(a) had thinner (p = 0.013) IMT in bifurcation [1.59 mm (95% CI 1.49; 1.68)] compared to the men in the highest [1.91 mm (95% CI 1.73; 2.09)] apo(a) quartile. The difference remained (p = 0.038) after adjusting for confounders. Plasma fibrinogen was not related to carotid IMT, whereas FPA correlated with common carotid (r = 0.21, p = 0.016) and carotid bifurcation (r = 0.21, p = 0.018) IMT. These associations abolished after adjusting for the confounders. The data suggest that apo(a) associate with carotid atherosclerosis independent of other risk factors for ischemic cardiovascular diseases.

Anthropometry↗
PubMed1992

Leukocyte count correlates in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study.

Cross-sectional associations between leukocyte count and sociodemographic and cardiovascular risk factors were investigated in 14,679 participants aged 45-64 years in the Atherosclerosis Risk in Communities Study carried out in four US communities in 1986-1989. Leukocyte count was strongly associated with present or past history of cigarette smoking and was higher in males than in females and in white subjects than in black subjects. Among never smokers, no sex differences were evident after adjustment for other risk factors. Race-associated differences were substantially reduced after other factors were taken into account in multivariate analyses. In never smokers, leukocyte count was higher in those who reported poor health, and it was inversely associated with high density lipoprotein cholesterol, forced expiratory volume at 1 second, physical activity, and, among whites, height and socioeconomic indicators. It was directly associated with indices of body weight and body fat, heart rate, blood pressure, hemoglobin, platelet count, uric acid, fasting insulin and glycemia, triglycerides, fibrinogen, antithrombin III, protein C, factors VII and VIII, and von Willebrand factor. The associations of leukocyte count with cardiovascular risk factors may either represent manifestation of subclinical disease or suggest that leukocyte count is part of the causal chain leading to atherosclerosis. Alternatively, the relation of leukocyte count to cardiovascular disease may be confounded by risk factors and thus be noncausal.

Arteriosclerosis↗
PubMed1992

The human carotid atherosclerotic plaque stimulates angiogenesis on the chick chorioallantoic membrane.

The chick chorioallantoic membrane was used to determine whether the carotid atherosclerotic plaque stimulates angiogenesis. Carotid endarterectomy specimens (1 mm3) with fibromuscular plaque (n = 8) and complicated plaque (n = 11) were implanted on the membrane on day nine of incubation and the response evaluated on day 11. Following fixation in situ with 10% formalin the angiogenic response was evaluated by: (1) examining whole membrane mounts, (2) quantitatively from a vascular density index and (3) from a histological study. Unmanipulated chorioallantoic membrane (n = 11) and plaque boiled prior to implantation (n = 6) served as controls. The vascularity of whole mounts of both fibromuscular and complicated plaque was greater than the controls. Vessel density of the membrane was estimated by counting the number of vessels intersecting four concentric circles (144.5 mm total circumference) placed on the formalin fixed membrane. The vascular density index due to the fibromuscular plaque (390.6 +/- 8.3) and complicated plaque (391.0 +/- 14.9) were similar (P greater than 0.9) but were significantly greater (P less than 0.001) than the unmanipulated membrane (327.9 +/- 5.6) or after treatment with the boiled plaque (283.8 +/- 15.6). Transforming growth factor beta 1 confirmed the validity of the experimental model to study angiogenesis. The histology of the chorioallantoic membrane due to either type of plaque was similar. Numerous vessels surrounded the plaque, and intraplaque vessels containing nucleated chick erythrocytes were observed. Although scattered vessels surrounded the boiled plaque, intraplaque vessels were not observed. This study demonstrates that the atherosclerotic plaque has angiogenic properties that may account for the increase in vasa vasorum that is associated with the plaque.

Allantois↗
PubMed1992

Leucocytes and free radicals in stable angina pectoris.

Bicycle ergometer exercise was used to induce ischemia in 20 patients with stable angina pectoris (SAP). Superoxide dismutase (SOD) blood concentrations, free radical generation (by the SOD-inhibitable reaction of ferricytochrome C), malondialdehyde (MDA) plasma concentrations, the unfractionated leucocyte filterability rate and the filterability rates of the granulocyte and mononuclear sub-fractions (using a positive pressure filtration system and 5 mu diameter Nuclepore filters), were monitored before and after exercise in the patients and in 18 matched controls. At the onset of ischemia a significant increase in the level of MDA plasma concentrations and significant decreases in both SOD blood concentrations and the SOD-inhibitable reduction of ferricytochrome C indicated oxygen free radicals had been released in the SAP patients. These changes were associated with significant impairments of granulocyte and unfractionated leucocyte filterabilities and with morphological evidence of granulocyte activation.

Aged↗
PubMed1991

Sympathetic vascular function in patients with central dysautonomia.

This study used digital photoplethysmography (d-FPG) to investigate alterations in skin blood flow after exposure to cold as well as the post-prandial blood pressure pattern to assess how the sympathetic branch of autonomic nervous system (ANS) functioned in 31 patients with cerebral dysautonomia and in 27 healthy controls. d-FPG was carried out on all ten fingers in basal conditions and after exposure to ice-cold water (4-5 degrees C). Amplitude, crest time and inclination time were used to calculate the alterations induced by the cold pressor test. After a standard lunch blood pressure was monitored every 20 minutes using a fully automatic non-invasive sphygmanometer. Unlike the controls the amplitude of the photoplethysmographic wave increased in all patients except 2; crest time and inclination time decreased in all except 3; post-prandial diastolic and systolic blood pressure levels fell markedly in all but 3. Blood vessel smooth muscle tone is disturbed in patients with ANS failure because dysautonomia may permit the action of vasodilating substances to predominate. The post-prandial blood pressure pattern and the d-FPG used in conjunction with a cold pressor test are useful tools in the non-invasive investigation of ANS function.

Autonomic Nervous System Diseases↗
PubMed1991

Tumours of the patella.

We report 15 cases of primary tumours and pseudotumours of the patella. The radiographic features and the surgical treatment of the different histological types are described in relation to Enneking's surgical staging and data derived from the literature.

Adolescent↗
PubMed1991

Use of pentoxifylline as an inhibitor of free radical generation in peripheral vascular disease. Results of a double-blind placebo-controlled study.

The effects of an infusion of pentoxifylline 1 g as an inhibitor of free radical generation have been determined in a double-blind placebo-controlled study. Leucocyte-derived free radical generation (by the superoxide dismutase-inhibitable reduction of ferricytochrome), the release of reactive oxygen metabolites (as plasma oxidant activity), unfractionated leucocyte and erythrocyte filterability rates (using a constant-flow positive-pressure system), plasma viscosity, and plasma fibrinogen concentration have been measured in two matched groups of 10 patients with Stage II peripheral vascular disease, before and after treatment. Transcutaneous oxygen pressure (PtcO2) during treadmill exercise to stress leg circulation was also measured. Leucocyte-derived free radicals were generated during peripheral ischaemia. Pentoxifylline inhibited their generation, blocked the release of reactive oxygen metabolites, and reduced impairment of the filterability rate of unfractionated leucocytes. The improvements were accompanied by significant shortening of the half-time of recovery of transcutaneous oxygen pressure, indicating that ischaemic damage had been contained.

Cross-Sectional Studies↗
PubMed1991

Prognostic value of the dense middle cerebral artery sign in patients with acute ischemic stroke.

The presence of a dense appearance of the horizontal part of the middle cerebral artery (the "dense middle cerebral artery sign") was looked for on CT scans taken on admission in 90 consecutive patients with ischemic stroke in the carotid artery distribution. The outcome of the 14 patients with the sign was poorer than that of 76 patients without the sign (Odds ratio 4.3). We suggest that this sign could be a useful prognostic variable in the acute phase of an ischemic stroke.

Brain Ischemia↗