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Biomedical subjects

A Cherchi

Publications and source records attributed to A Cherchi.

At least 19 recordsLinked to original sources
PubMed2001

Can menopause be considered an independent risk factor for cardiovascular disease?

Following the menopause, women develop coronary artery disease at the same rate as men. The best documented change observed in the risk factors linked to ovarian exhaustion is an alteration in lipid composition. More recent studies, however, suggest that the increased cardiovascular morbidity and mortality after menopause cannot be fully explained by changes in plasma lipoproteins, and support the concept that ovarian hormone deprivation has a widespread impact on the cardiovascular system, with a direct harmful effect on vessel-wall physiology. After the menopause, subjects free from cardiovascular diseases show vascular hyperactivity and a poor vasodilator reserve; the rate of increase in the incidence of arterial hypertension in women is higher than that observed among males of the same age; altogether, cardiovascular diseases become the number one cause of death among women. A large number of mechanistic studies have shown that estrogens, through either direct or genomic-dependent activities, produce beneficial effects on the factors controlling blood flow and plaque formation. Nevertheless, results from recent randomized clinical trials are challenging the belief that postmenopausal hormone therapy protects against coronary artery disease.

Arteriosclerosis↗
PubMed1999

Effects of acute administration of natural progesterone on peripheral vascular responsiveness in healthy postmenopausal women.

Peripheral vascular responses to acute administration of natural progesterone were studied in 12 postmenopausal women (mean +/- SD age 50.3 +/- 4.8 years) with no evidence of cardiovascular disease. According to a randomized, double-blind protocol, all subjects were given natural progesterone as a vaginal cream, able to produce a rapid peak and decay of plasma hormone concentrations, or matched placebo, with crossover after a 1-week washout period. Forearm blood flow and peak flow after ischemic stress (ml/100 ml/min), local vascular resistance (mm Hg/ml/100 ml/min), venous volume (ml/100 ml), and venous compliance (ml/100 ml/mm Hg) were measured by strain-gauge venous occlusion plethysmography at baseline and after progesterone or placebo administration. Plasma norepinephrine concentrations were determined by high-performance liquid chromatography with electrochemical detection. Progesterone sharply decreased forearm blood flow (p <0.01) through an increase in local vascular resistance (p <0.01). Measures of venous function remained unchanged. Although the hormone increased circulating norepinephrine concentrations (p <0.05), there were no significant changes in mean arterial pressure or heart rate. Furthermore, progesterone reduced the local vasodilator capacity, shown by a decrease in forearm delta flow (difference between peak flow and basal flow, p <0.05). Compared with the well-known effect of estrogen, progesterone exerted an opposite action on peripheral vascular responsiveness. Peripheral circulatory changes may be attributed to a direct activity of progesterone on the arterial wall and may in part reflect a modulation of the hormone on peripheral sympathetic tone. Consideration must be given to the hypothesis that the addition of progestin may attenuate the beneficial effects of unopposed estrogen replacement therapy in postmenopausal women.

Cardiovascular Physiological Phenomena↗
PubMed1999

Study of myocardial contractility by pulsed wave Doppler tissue imaging does not reveal an inotropic effect of estrogen at physiologic dose.

We studied myocardial contractility by pulsed wave Doppler tissue imaging in 6 postmenopausal healthy women. According to a crossover, double-blind protocol, we randomized patients to treatment with transdermal patches of estradiol-17beta or matched placebo. Estradiol-17beta did not modify local systolic and diastolic functions. Thus, at least when acutely administered, estrogen seems to be unable to determine hemodynamic changes at the myocardial level, in opposition to what occurs in the peripheral vascular system.

Administration, Cutaneous↗
PubMed1999

Impaired forearm blood flow and vasodilator reserve in healthy postmenopausal women.

BACKGROUND: The natural process of cessation of ovarian estrogen production is associated with an increasing incidence of cardiovascular disease. OBJECTIVE: We aimed to determine whether postmenopausal women had menopause-associated vasomotor disturbances develop. METHODS: We studied the vascular forearm function using strain-gauge venous occlusion plethysmography in 12 healthy postmenopausal women (mean age +/- SD, 47 +/- 3 years; time-lapse from menopause >1 year). Twelve premenopausal subjects matched for age and biophysical characteristics were used as a control group. RESULTS: No differences were observed in heart rate or mean blood pressure between the 2 groups of women. Forearm blood flow at supine resting was lower in postmenopausal than in premenopausal women (2.4 +/- 0.8 vs 3.1 +/- 0.5 mL/100 mL/min; P <.05). Local vascular resistance was higher in postmenopausal than in premenopausal women (43.5 +/- 17.5 vs 31.1 +/- 4.3 mm Hg/mL/100 mL/min; P <.05). Moreover, peak forearm flow in response to forearm ischemia was 20.8 +/- 7.9 mL/100 mL/min in postmenopausal women and 26.6 +/- 9.7 mL/100 mL/min in premenopausal women (P <.01). Plasma concentration of noradrenaline in the supine position was significantly higher in postmenopausal than in premenopausal women (286 +/- 22 pg/mL vs 195 +/- 33 pg/mL; P <.01). Finally, a significant positive relation was revealed in postmenopausal women between the amount of vasodilator reserve (D flow) in local peripheral circulation and levels of circulating estradiol-17beta. CONCLUSIONS: Abnormalities observed in forearm blood flow and vasodilator capacity in postmenopausal women may be attributed to a critical loss of the vasodilating property of physiologic estrogen. Our data support the possibility that reduction in dilator capacity of the vasculature may contribute to the increase of cardiovascular disease after menopause.

Blood Pressure↗
PubMed1998

Estradiol-17beta reduces blood pressure and restores the normal amplitude of the circadian blood pressure rhythm in postmenopausal hypertension.

After menopause, both systolic (SBP) and diastolic (DBP) blood pressure (BP) become higher in women than in men of the same age, suggesting that estrogen deficiency may influence the age-related increase in BP. We studied 30 postmenopausal women (mean age, 55 +/- 5.7 years; time from menopause, 2-5 years) affected by mild hypertension with no target-organ complications by means of 24-h BP monitoring. None of the group were undergoing estrogen replacement therapy or taking antihypertensive drugs. According to a randomized, double-blind protocol, subjects received patches of transdermal estradiol-17beta (E2) or a matched placebo, with crossover after a 7-day washout period. In 12 patients the 24-h peak-to-trough variation in SBP and DBP amounted to less than 10% (nondippers). Administration of E2 significantly decreased 24-h SBP and DBP in the whole cohort (P < .05). Furthermore, E2 restored the expected reduction in BP during nighttime in the nondipper subgroup. It is well known that estrogen replacement therapy protects against the development of both cardiovascular diseases and stroke. Our data suggest that this activity could be attributed, at least in part, to the activity of E2 in preserving physiologic circadian fluctuation of BP.

Aged↗
PubMed1998

Association between dopamine receptor genes and migraine without aura in a Sardinian sample.

BACKGROUND: Migraine seems to be caused by a combination of environmental and genetic factors. Clinical and pharmacologic evidence supports the hypothesis that dopaminergic transmission is involved in the pathogenesis of migraine. OBJECTIVE: The current report concerns a genetic study to test the involvement of genes for dopamine (DA) receptors D2 (DRD2), D3 (DRD3), and D4 (DRD4) in migraine without aura, particularly in a subgroup with enhanced DA sensitivity. METHODS: For the first time, a family-based association method--the Transmission Disequilibrium Test (TDT)--was used to examine an isolated population, such as Sardinians. We studied 50 nuclear families of patients affected by migraine without aura. The subgroup of dopaminergic migraineurs was selected based on the presence of both nausea and yawning immediately before or during the pain phase of migraine. RESULTS: No association was detected using the TDT between DRD3, DRD4, and migraine without aura either in the overall sample or in the subgroup. No difference was observed in DRD2 allelic distribution in the overall sample, although the allelic distribution at the DRD2 locus differed significantly in the subgroup of dopaminergic migraineurs (p = 0.004). Allele 1 of the TG dinucleotide intronic noncoding polymorphism of the DRD2 locus was the individual allele that appeared to be in disequilibrium with migraine without aura (p = 0.02). CONCLUSIONS: Our data suggest that a genetic approach could be useful in providing molecular support to the hypothesis that hypersensitivity of the dopaminergic system may represent the pathophysiologic basis of migraine, at least in a subgroup of patients.

Adolescent↗
PubMed1997

Effects of acute administration of transdermal estrogen on postmenopausal women with systemic hypertension.

We studied 16 postmenopausal women with mild to moderate hypertension according to a randomized, double-blind protocol. They received patches of transdermal estradiol-17beta rated to deliver 100 mg/day of substance or matched placebo. A 24-hour ambulatory blood pressure (BP) monitoring was performed at baseline and after drug administrations. Our data show that estradiol-17beta exerts beneficial effects, both in lowering elevated BP levels and in maintaining a uniform BP control over 24 hours. Estrogen replacement therapy could be considered when significant changes in BP occur during the postmenopausal period.

Administration, Cutaneous↗
PubMed1997

Association between psychiatric disorders and Marfan's syndrome in a large Sardinian family with a high prevalence of cardiac abnormalities.

BACKGROUND: Marfan's syndrome is an inherited disorder of connective tissue associated with characteristic abnormalities of the skeletal, ocular, and cardiovascular systems. Marked clinical variability and age dependency of all manifestations of Marfan's syndrome may render the unequivocal diagnosis difficult in mildly affected, young subjects. HYPOTHESIS: The study and care of a 32-year-old woman with evidence of Marfan's syndrome, several cardiac abnormalities, and paranoid schizophrenia led to an investigation of her consenting relatives to verify the penetrance of Marfan's syndrome and the degree of comorbidity between the disease and psychiatric disorders. METHODS: The patient and 12 subjects belonging to three generations of her family underwent cardiovascular, skeletal, ophthalmologic, and psychiatric examinations. Two-dimensional and Doppler echocardiography were performed. RESULTS: One female index patient and six of her first-degree relatives were found to be affected by Marfan's syndrome. All seven patients were found to have mitral valve prolapse associated with other cardiac abnormalities. Four of these patients were affected by the following psychiatric disorders: generalized anxiety disorder, major depressive disorder, paranoid schizophrenia (two cases). Six more relatives without Marfan's syndrome showed mitral valve prolapse in association with other echocardiographic features. Two of these were found to be affected by a major depressive disorder. CONCLUSIONS: The present data support the hypothesis that a psychiatric condition, associated with a significantly high frequency of cardiac involvement, may be part of the phenotype of Marfan's syndrome.

Adolescent↗
PubMed1997

[Does a genetic predisposition for infarction expansion exist? Evaluation of genetic polymorphisms of the renin-angiotensin system].

Aim of this study is to carry out a genetic analysis of polymorphisms of the renin-angiotensin system in a genetically homogeneous population, in patients with and without myocardial infarction (AMI) expansion and to evaluate the influence of non genetic, mechanical factors. The study was conducted on 299 patients with first AMI. Ecocardiography studies were performed on all patients on day 1 and 3 from the onset of AMI and before discharge. Eighty-four patients were excluded because of inadequate quality of echocardiograms and 215 (163 males, 52 females) were admitted. Of these, 157 had no evidence of AMI expansion (EXP-) while 58 had expansion (EXP+). DNA was extracted by standard methods from blood samples. Age and gender had no influence on AMI expansion. Anterior infarction (p < 0.000001) and Q-wave infarction (p < 0.00002) were found more frequently in EXP+. Peak of creatine phosphokinase was higher in EXP+ than in EXP- (p < 0.00001). The percent of patients treated with thrombolysis or with hypertension and/or left ventricular hypertrophy was not significantly different in the two groups. AGT MT235 polymorphism of angiotensinogen gene, I/D polymorphism of ACE gene and AT1 A1166C of AT1 receptor of angiotensin II were not significantly different in two groups. Stratified analysis showed that in patients with anterior AMI (n = 87), with a higher risk of AMI expansion, there is a significant difference (p < 0.02) in ACE genotype between EXP- and EXP+. Odds ratio assuming the dominant effect of I allele (II+ ID < DD) was 3.35 (confidence interval 1.41-7.56) with increased risk of expansion. More extension studies are need to verify if these results can contribute to early identification of patients at higher risk and to optimize therapeutic approach.

Aged↗
PubMed1996

Six-year follow-up of thyroid function during lithium treatment.

A cohort of patients at various stages of lithium treatment was followed up for 6 years in order to evaluate the course of thyroid abnormalities. Ultrasonography confirmed that lithium can increase thyroid size, especially in cigarette smokers, and that it can affect the texture of the gland. However, the incidence of clinical hypothyroidism or specific thyroid autoimmunity does not exceed that found in the general population. Repeated determinations of thyrotrophin (TSH) concentrations can prevent clinically relevant consequences. Addition of carbamazepine to lithium can counteract lithium-induced subclinical hypothyroidism, possibly improving prophylactic efficacy in recurrent affective disorders.

Antibodies↗
PubMed1995

Echocardiographic assessment of aortic valve replacement with stentless porcine xenografts.

Stentless porcine xenografts (SPXs) implanted in the aortic position have potential hemodynamic advantages over traditional valve prostheses because of the lack of a rigid stent. Twenty-four patients (mean age 59 years) who underwent aortic valve replacement with SPXs were studied by echocardiography early after and 26 +/- 10 months (range 8 to 40) after operation. Peak and mean gradients, as well as aortic valve area, did not change significantly from baseline (16.3 +/- 8 and 9.8 +/- 5.6 mm Hg, and 1.78 +/- 0.63 cm2, respectively) to follow-up study (12.5 +/- 5 and 7.7 +/- 3 mm Hg, and 1.8 +/- 0.65 cm2, respectively). At baseline, color flow Doppler imaging showed aortic valve regurgitation where the leaflets coapted centrally in 17 of 24 patients (trivial, n = 14; mild, n = 3). Besides the central leak, paravalvular regurgitation was seen in 4 patients (trivial, n = 3; mild, n = 1). At follow-up, 18 of 24 patients had aortic valve regurgitation (trivial, n = 11; mild, n = 6; and moderate, n = 1). New valvular regurgitation (graded as trivial, n = 2; mild, n = 2; and moderate, n = 1) was detected in 5 patients, and new paravalvular regurgitation (graded as mild) developed in 1 patient. Two patients underwent repeat operation for valve-related complications: (1) rupture of a valve cusp with acute pulmonary edema, and (2) fibrotic stenosis of the left coronary ostium with unstable angina. In conclusion, this study demonstrates good hemodynamic performance of the SPX in the aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Intracranial haemorrhage during exercise testing.

We describe the occurrence of an intraparenchymal (thalamic) haemorrhage during a stress test in a hypertensive 52-year-old man who had suffered from myocardial infarction 3 months earlier. Common causes of spontaneous haemorrhage, such as arteriovenous malformation, aneurysms, neoplasm, bleeding disorders or vasculitis were excluded. This single neurological complication was observed from among 8000 exercise tests performed in our Institute from 1987 to 1993.

Cerebral Angiography↗
PubMed1995

[Hemodynamic assessment at rest and during dynamic physical exercise in young subjects with and without hypertensive parents].

The aim of this research was to identify any early cardiovascular changes that may be predictive of future hypertension in young subjects with family history of hypertension. The study was conducted on 25 offspring of hypertensive parents, mean age 17 years (22 with hypertension only in 1 parent and 3 with both hypertensive parents) and 20 offspring of both normotensive parents, matched by age. Subjects were divided into children (7-13 years) and young adults (19 years on). All subjects underwent three office blood pressure measurements with a mercury sphygmomanometer. On the third control, BoMed thoracic electrical bioimpedance at rest and during upright bicycle exercise was performed. Physical characteristics were similar in subjects matched by age in the two groups. Systolic blood pressure was similar in offspring of normotensives and hypertensives, both at rest and during exercise; diastolic blood pressure was greater in offspring of hypertensive parents at rest (73.1 +/- 10.5 vs 63.5 +/- 7.1 mmHg, p < 0.05), during the first minutes of exercise and during the recovery phase (p < 0.05). Moreover, at the third blood pressure measurement at rest, diastolic blood pressure decreased, with respect to the first measurement, only in children and young adult offspring of normotensive parents, while systolic blood pressure decreased in the two groups of child subjects. No differences in heart rate were observed, both at rest and during physical exercise, between offspring of normotensives and hypertensives. Left ventricular end-diastolic volume, stroke volume, ejection fraction, cardiac output and systemic vascular resistance at rest and their response to decubitus changes and exercise were normal and similar in offspring of normotensive and hypertensive parents both in children and young adults. In conclusion, a different behavior of diastolic blood pressure was found in offspring of hypertensive parents compared to that of normotensive parents, both in children and, to a higher degree, in young adults. This may be an expression of early vascular change in subjects with a genetic predisposition to hypertension.

Adolescent↗
PubMed1993

Intraoperative echocardiography by a new miniaturized epicardial probe: preliminary findings.

Miniaturized probes constitute recent progress in the field of epicardial echocardiography. We recently used a new miniaturized probe, derived from a standard transesophageal probe, in a series of 12 adult patients who underwent cardiac surgery in order to test the possibility of obtaining new views for epicardial imaging. This study demonstrates the feasibility and safety of performing intraoperative echocardiography when using a miniaturized epicardial probe. This probe may be placed on a broader epicardial and vascular area, thus overcoming the size limitations of the commonly used epicardial probes. The major limitation found with the miniaturized probe, however, was the inability to obtain a true four-chamber view from the ventricular apex, due to the difficulty of holding the probe motionless between the apex and the diaphragm while the heart is beating. Although extensive experience with larger groups of patients and different pathologies will be required to define the full potential of this new probe, the advent of the miniaturized probe may further expand the applicability of epicardial echocardiography in pediatric patients during surgery for congenital heart disease.

Adolescent↗