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Biomedical subjects

L Gabrielli

Publications and source records attributed to L Gabrielli.

At least 37 records · Page 2Linked to original sources
PubMed1996

Gonadotropin-releasing hormone agonist-induced hypoestrogenism and blood flows in cerebral arteries.

OBJECTIVE: To evaluate the effect of the hypoestrogenism induced by GnRH agonist (GNRH-a) therapy on cerebral vessel blood flow. DESIGN: Open, controlled study. SETTING: Tertiary care units of the University of Milan, Italy. PATIENTS: Young women scheduled to undergo 6 months of therapy with a GnRH-a; a control group was also enrolled. INTERVENTIONS: In both groups, the pulsatility index of both the internal carotid artery (ICA) and middle cerebral artery (MCA) was measured by means of Doppler ultrasound over a period of 6 months. MAIN OUTCOME MEASURE: The ICA and MCA pulsatility index. RESULTS: No variation in the pulsatility index of either artery was found in either group. CONCLUSIONS: A 6-month period of GnRH-a-induced hypoestrogenism in young women does not lead to any variation in the blood flow of cerebral vessels. This provides some reassurance as to the safety of these drugs in relation to the role that the reactivity of peripheral arteries may play in determining risk of cardiovascular disease. Furthermore, our results show that blood flow in the cerebral vessels of young subjects is under extraestrogenic control and that this may counterbalance estrogen deprivation through mechanisms that probably are no longer active in the perimenopausal years.

Adult↗
PubMed1996

Alteration in the pulsatility index values of the internal carotid and middle cerebral arteries after suspension of postmenopausal hormone replacement therapy: a randomized crossover study.

OBJECTIVE: The aim of the study was to investigate the effect of the suspension of hormone replacement therapy on blood flow in the internal carotid and the middle cerebral arteries. STUDY DESIGN: Doppler ultrasonography was used to measure the pulsatility index of the internal carotid and middle cerebral arteries of 23 women. The patients were all receiving continuous transdermal estradiol replacement therapy (50 micrograms/day) with a cyclic supplementation of medroxyprogesterone acetate every second month (10 mg/day for 12 days). The duration of the study was 12 months. The patients were randomly assigned to one of two groups. The first group (11 subjects) continued therapy for the first 6 months and then suspended it for the following 6 months; the second group (12 subjects) interrupted hormone replacement therapy for the first 6 months and then resumed it for the following 6 months. The internal carotid and middle cerebral artery pulsatility index was measured at the start of the 12-month period and then every 3 months. Serum estradiol levels were measured to check compliance. RESULTS: A statistically significant difference was found between the internal carotid and middle cerebral artery pulsatility index values of the two groups at each of the measurements after the first one. Over the first 6 months the pulsatility index values rapidly increased in the patients kept off hormone replacement therapy and remained stable in those receiving hormone replacement therapy. After the crossover at 8 months, the pulsatility index rapidly dropped to values similar to those at baseline in the patients who resumed hormone replacement therapy and increased in those who suspended therapy. CONCLUSIONS: Resistance to blood flow in cerebral vessels of postmenopausal women rapidly changes after hormone replacement therapy suspension. In postmenopausal women estrogen administration should be continued to maintain the favourable variations of vascular reactivity induced by hormone replacement therapy.

Body Mass Index↗
PubMed1995

Modulation of electrically elicited blink reflex components by visual and acoustic prestimuli in man.

The effects of a prestimulus on the electrically elicited blink reflex components were investigated in 20 healthy subjects. In the first group of 10 subjects (warned group), electric shocks were delivered in isolation or preceded, at an interstimulus interval (ISI) of 0.1 s, 1 s, or 10 s, by a visual or acoustic warning stimulus. In the second group of 10 subjects (unwarned group), the electric shocks were delivered either in isolation or preceded, at the same ISI, by visual or acoustic stimuli having no warning value. The modulation of the three blink reflex components was then analysed. Compared to the baseline condition, the R1 oligosynaptic component was enhanced at 0.1 s and 1 s ISI, in the warned group with the visual prestimulus, but only at 0.1 s after a visual and acoustic prestimulus in the unwarned group. On the contrary, the polysynaptic responses showed a different course: R2 was significantly reduced at the 0.1 s interval in the warned group with both the prestimuli, and only with the visual prestimulus in the unwarned group. The R3 was inhibited at all three intervals with the visual prestimulus, and at the 0.1 s and 1 s with the acoustic one in the warned group, and only at 0.1 s in the unwarned group, both after visual and acoustic prestimuli. The decrement in R2 and R3 observed with the shortest interval was probably related to the prepulse inhibition of startle reflex. Furthermore, only R3 was still inhibited at longer intervals, when the sustained processes of attention may have influenced this component. Perhaps this combination of events represents, in the warned group, the best preparation for voluntary reflex reaction.

Acoustic Stimulation↗
PubMed1994

Association of increased fibrin turnover and defective fibrinolytic capacity with leg atherosclerosis. The PLAT Group.

Patients with peripheral arterial disease have a high risk of death from cardiovascular events. As defective fibrinolysis associated with leg atherosclerosis has been suggested as a predisposing factor, we sought a relation among decreased fibrinolysis, the presence of leg atherosclerosis and the incidence of thrombotic events in a case-control study nested in the PLAT. Fifty-eight patients with coronary and/or cerebral atherothrombotic disease, free of leg atherosclerosis at Doppler examination, were compared with 50 atherosclerotic patients with leg involvement. High D-dimer (153.0 vs 81.3 ng/ml, p < 0.001) and tPA antigen before venous stasis (14.4 vs 11.8 ng/ml, p < 0.03), and low tPA antigen (6.7 vs 15.6 ng/ml, p < 0.01) and fibrinolytic activity released after venous stasis (fibrinolytic capacity: 113.2 vs 281.4 mm2, p < 0.001) were found in patients with leg atherosclerosis. D-dimer and fibrinolytic capacity, in addition to age, were selected by stepwise discriminant analysis as characterizing patients with leg atherosclerosis. Moreover, higher D-dimer and tPA inhibitor characterized patients with leg atherosclerosis who subsequently experienced thrombotic events. These findings constitute evidence of high fibrin turnover and impaired fibrinolytic potential in patients with leg atherosclerosis. Thus impaired fibrinolysis may contribute to the prothrombotic state in these patients.

Aged↗
PubMed1993

Blood flow variations in internal carotid and middle cerebral arteries induced by postmenopausal hormone replacement therapy.

OBJECTIVE: Our purpose was to clarify the mechanisms by which postmenopausal estrogen replacement therapy exerts its protective effect on cardiovascular risk. STUDY DESIGN: By means of a bidirectional Doppler ultrasonographic system we measured pulsatility index variations the internal carotid artery and middle cerebral artery in 25 early postmenopausal women during a 6-month period of hormone replacement therapy. Transdermal estradiol (50 micrograms/day) was continuously administered. A 12-day course of medroxyprogesterone acetate (10 mg/day) was added every second month. RESULTS: The pulsatility index showed a significant (p = 0.0001) reduction in both arteries after 6 weeks. At 22 weeks a 25% reduction was measured. No variation of the estrogen-induced pulsatility index reduction was observed at the end of every cyclic progestogen supplementation. CONCLUSIONS: In early postmenopausal women hormone replacement therapy causes a rapid reduction of pulsatility index in brain arteries. Cyclical progestational supplementation does not modify this positive effect on reactivity of the blood vessels.

Administration, Cutaneous↗
PubMed1993

Increased fibrin turnover and high PAI-1 activity as predictors of ischemic events in atherosclerotic patients. A case-control study. The PLAT Group.

A case-control comparison within the framework of the prospective, multidisciplinary PLAT Study was performed to assess whether altered baseline fibrinolytic variables were associated with an elevated risk of ischemic thrombotic events in patients with documented coronary, cerebral, and/or peripheral atherosclerotic disease. Fibrinogen, D-dimer, tissue plasminogen activator (t-PA) antigen, and fibrinolytic activity before and after venous stasis (delta = difference between the two values), t-PA inhibitor, and lipid levels in 60 atherosclerotic patients with a thrombotic event during the first year of follow-up were compared with those in 94 atherosclerotic patients without such events, who were matched for age, sex, and diagnosis at enrollment. Events were associated with a higher release of delta t-PA antigen (P = .047), higher D-dimer (P = .024), and higher t-PA inhibitor (P = .001) levels. delta Fibrinolytic activity was correlated inversely with t-PA inhibitor (P < .01) and triglycerides (P < .05). D-Dimer was also correlated with systolic blood pressure (P < .01). Atherosclerotic patients at higher risk of thrombotic ischemic events are characterized by increased fibrin turnover and impaired fibrinolytic activity due to high t-PA inhibitor levels. This hemostatic disequilibrium may participate with conventional risk factors such as elevated triglyceride levels and systolic blood pressure in the multifactorial mechanism of ischemic sequelae in patients with preexisting vascular atherothrombotic disease.

Aged↗
PubMed1993

[The role of iloprost in vascular surgery].

Use of prostanoids in vascular surgery is valuable in various conditions: intra and postoperatively, during limb salvage procedures, they are useful to lower peripheral resistances, and in patients with limited gangrene, when surgery is not feasible, they improve limb blood flow. After some years of subjective clinical evaluation, multicentric randomized clinical trials started; the aim was to quantify the real benefit derived from the use of prostanoids to the evolution of limb ischemia and to the improvement of results of surgical revascularization. We have not yet definitive results; preliminary data show a better immediate patency rate of femoro-distal bypass grafts and a critical reduction in long term limb amputations.

Clinical Trials as Topic↗
PubMed1992

The PLAT Study: hemostatic function in relation to atherothrombotic ischemic events in vascular disease patients. Principal results. PLAT Study Group. Progetto Lombardo Atero-Trombosi (PLAT) Study Group.

The Progetto Lombardo Atero-Trombosi (PLAT) Study was a prospective, multicenter, multidisciplinary study of the association among hemostatic variables, conventional risk factors, and atherothrombotic events in four groups of patients with preexisting vascular ischemic disease (335 myocardial infarction survivors, 123 patients with stable angina pectoris, 160 with transient ischemic attacks, and 335 with peripheral vascular disease). In the myocardial infarction group, univariate analysis showed that atherothrombotic events were associated with high fibrinogen (p = 0.001), factor VIII:C (p less than 0.001), and von Willebrand factor antigen (vWF:Ag) (p = 0.004) levels and with low high density lipoprotein cholesterol (p = 0.043), factor VII (p = 0.019), and protein C (p = 0.044) levels; multivariate analysis produced associations with high fibrinogen and factor VIII:C levels and low protein C levels. By both univariate and multivariate analysis, events in the angina pectoris group were associated with high vWF:Ag (p = 0.026) and leukocyte (p = 0.033) levels and the presence of carotid arterial stenosis (p = 0.063); associations with high leukocyte (p = 0.037) and factor VIII:C (p = 0.186) levels, family history (p = 0.031), and diabetes (p = 0.061) were also found in the group with transient ischemic attacks. In those with peripheral vascular disease, events were associated with Fontaine stage greater than or equal to IIB (p = 0.024), high factor VIII:C levels (p = 0.073), and low protein C (p = 0.028), fibrinogen (p = 0.030), antithrombin III (p = 0.054), and factor VII (p = 0.057) levels by univariate analysis and with Fontaine stage and low fibrinogen levels by multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

The PLAT Study: a multidisciplinary study of hemostatic function and conventional risk factors in vascular disease patients.

In this paper are reported the basal results of a multidisciplinary, multicenter study designed to explore in a population with ischemic disease the relation between hemostatic variables, conventional risk factors and atherothrombotic sequelae. 953 patients less than or equal to 69 yrs with documented coronary, cerebral or peripheral atherosclerotic disease were studied and followed-up for 24 months. Examinations included hemostatic and lipid laboratory assays, arterial Doppler examination, cerebral computerized tomography and nuclear magnetic resonance, exercise electrocardiogram and coronary angiography. Fibrinogen (301.4 +/- 71.52 mg/dl) correlated positively with antithrombin III (r = 0.27) and leukocytes (r = 0.25), negatively with HDL-cholesterol (r = 0.18) and tended to increase with smoking. Heavy smokers had higher leukocyte counts than non-smokers (8.0 +/- 2.0 vs. 7.2 +/- 2.1 x 10(3)/microliters), higher triglycerides (1.87 +/- 1.12 vs. 1.53 +/- 1.35 mmol/l) and lower HDL-cholesterol (0.93 +/- 0.27 vs. 1.00 +/- 0.25 mmol/l). FVII correlated positively with triglycerides (r = 0.16) and protein C (r = 0.45). vWF:Ag (145.4 +/- 70.58%) ad FVII:C (139.7 +/- 59.10%) were positively correlated (r = 0.44). FVIII:C correlated positively with fibrinogen (r = 0.21). Myocardial infarction survivors with associated cerebral and peripheral vascular lesions had higher FVIII:C, FVII, fibronogen and vWF:Ag. These findings suggest that hemostatic factors may enhance and/or mediate the effects of conventional risk factors in atherothrombotic ischemic events.

Aged↗
PubMed1981

[New trends in the treatment of trophic sequelae post-phlebitic syndrome].

Authors analyses most recent concepts on pathogenesis of trophic changes in post-phlebitic syndrome: particularly they consider the role of extravascular fibrin deposition, in patients with depressed plasmatic fibrinolytic activity. In this patients, according to recent reports, it seems useful a fibrinolytic therapy to improve trophic conditions of the post-phlebitic limb, particularly in respect to dermatoliposclerosis. Authors refer their experience on a double blind study with stanozolol an anabolizing steroid with fibrinolytic activity: in all treated patients good clinical results were obtained; however no enhancement of plasmatic fibrinolytic activity was demonstrated.

Adult↗
PubMed1980

[Surface recording technique of His bundle potential in man].

A method is presented for the non-invasive recording of His bundle electrical activity from the body surface in man. Several bipolar ECG leads were employed: precordial, Frank "x" and Frank "z". Signals were filtered (30-300 Hz), highly amplified (5 x 104) and averaged. Digital averaging was performed on line by a microcomputer (OTE Biomedica Neuroaverager mod. 1172). Surface investigation was performed in 10 patients affected by different conduction pathology simultaneously with HBE recordings for diagnostic purpose and in 5 normal volunteers only incruently. Highly repeatable electrical deflections (B waves) were recorded in the PR segment. In all patients a good correspondence between surface (B wave) and intracardiac (H wave) was found. Atrial pacing and pharmacological test were used in order to ascertain the real source of B wave.

Bundle of His↗
PubMed1980

[Epidemiological evaluation of thromboembolic risk. Critical review of the prospects offered by determination of antithrombin III].

Authors review the epidemiology of deep venous thrombosis and the prothrombotic state in high risk patients; particularly antithrombin III role in blood clotting is considered. A fall in antithrombin III concentration and/or activity can induce hypercoagulability and thrombosis. Moreover authors stress the need to evaluate antithrombin III as anti-Xa activity, to detect high risk patients for deep venous thrombosis.

Antithrombin III↗