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Biomedical subjects

A Raineri

Publications and source records attributed to A Raineri.

At least 19 recordsLinked to original sources
PubMed1991

Subjective probability and delay.

Human subjects indicated their preference between a hypothetical $1,000 reward available with various probabilities or delays and a certain reward of variable amount available immediately. The function relating the amount of the certain-immediate reward subjectively equivalent to the delayed $1,000 reward had the same general shape (hyperbolic) as the function found by Mazur (1987) to describe pigeons' delay discounting. The function relating the certain-immediate amount of money subjectively equivalent to the probabilistic $1,000 reward was also hyperbolic, provided that the stated probability was transformed to odds against winning. In a second experiment, when human subjects chose between a delayed $1,000 reward and a probabilistic $1,000 reward, delay was proportional to the same odds-against transformation of the probability to which it was subjectively equivalent.

Adult↗
PubMed1991

[Effect of ticlopidine and dipyridamole on platelet aggregation and count in patients with chronic stable angina pectoris].

PURPOSE: To compare the ticlopidine and dipyridamole effects on platelets count and aggregation in patients with stable coronary artery disease. PATIENTS AND METHODS: Eighty patients with stable coronary artery disease and mean of 58.3 +/- 5.8 years were studied. They were divided into two equal groups of 40 patients and each one treated with ticlopidine or dipyridamole. Platelets count and aggregation were examined before treatment and at first and fourth weeks of treatment. RESULTS: At the end of fourth week of treatment, spontaneous, induced by ADP or by adrenalin platelet aggregation inhibition was observed, respectively, in 82.5%, 72.5% e 67.5% of the patients in ticlopidine group. The spontaneous, induced by ADP or by adrenalin, platelet aggregation inhibition in the patients of dipyridamole group was, respectively, 40%, 30% e 27.5% (p less than 0.001). The platelets count did not change in both groups. CONCLUSION: The ticlopidine effect is much more evident in platelet aggregation inhibition than dipyridamole, and maybe a choice in the prevention of cardiovascular events.

Coronary Disease↗
PubMed1990

Erythrocyte endogenous proteinase activity during blood bank storage.

We studied proteolytic alterations of membrane proteins in ghosts derived from human red blood cells, preserved up to 35 days in the liquid state either as whole blood or with additive solution. The study was carried out by performing sodium dodecyl sulfate polyacrylamide gel electrophoresis of stromal proteins from erythrocytes, either previously treated with proteinase inhibitors or previously incubated in conditions promoting proteolysis. To differentiate the effect of erythrocyte from granulocyte proteinases, the investigation was also carried out in leukocyte-free red cell preparations. The results show: (1) the effects of endogenous proteinases on membrane proteins derived from red cells stored under blood bank conditions; (2) a decrease of proteolytic effects in ghosts derived from red cells which have been submitted to a longer storage; (3) a relevant influence of the red cell resuspending medium before lysis on the time-dependent onset and exhaustion of proteolysis in ghosts. The presence of increased proteolysis in ghosts could be regarded as a marker of molecular lesions induced in red cells by storage under blood bank conditions.

Blood Preservation↗
PubMed1990

[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure].

To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences concerning casual BP determined in the morning (178.3/108.4 vs 171.5/106.2 mmHg). After a pharmacological washout of 2 weeks, patients underwent a noninvasive, intermittent, monitoring of BP (every 15 min during daytime and every 30 min from 11 pm to 7 am), using a pressure meter II Del Mar Avionics, and a continuous monitoring of ECG for 24 hours, employing an instrument 445/B Del Mar Avionics. Mean 24-hour BP was not different in the 2 groups of patients (161.7/99.0 vs 158.2/98.3 mmHg); however, patients with LVH showed a significantly greater variability of BP in the morning (7 am-3 pm), while mean 24-hour HR was significantly less (71.6 vs 78.2 b/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Short- and long-term effects of enalapril on the left ventricular function in patients with congestive heart insufficiency].

Several studies have demonstrated that enalapril causes a clinical and hemodynamic improvement in patients with congestive heart failure. Nevertheless, the drug capability of influencing left ventricular systolic and diastolic indexes has not been evaluated. In 12 patients with severe congestive heart failure (NYHA class III-IV), treated with digitalis and diuretics, we performed a baseline evaluation through a right heart catheterization, echocardiography and radionuclide ventriculography. The effects on left ventricular systolic and diastolic function indexes after the administration of enalapril 5 mg by oral route have been evaluated. After 3 months of chronic therapy with enalapril 5 mg twice daily, we performed a further evaluation through echocardiography and radionuclide ventriculography. At the acute test we observed a significant improvement of left ventricular ejection fraction (EF), left ventricular stroke index (LVSI), and peak of filling rate (PFR), with a significant reduction of pulmonary wedge pressure (PWP) and peripheral vascular resistance (PVR). After 3 months of chronic therapy EF was significantly increased with respect to baseline values (37 +/- 6.9% vs 28.7 +/- 7.9%, p less than 0.05) and showed a further increase after the drug administration (from 37 +/- 6.9% to 48 +/- 5.4%, p less than 0.001). PFR showed a similar behaviour and reached at the follow-up evaluation normal values (from 1.97 +/- 0.7 edv/s to 2.57 +/- 0.6 efv/s, p less than 0.001). Furthermore, the echocardiographic dimensions of the left ventricle decreased significantly with a significant increase of shortening fraction. In conclusion, our study demonstrates that in patients with severe congestive heart failure enalapril improves the left ventricular systolic and diastolic function indexes and this improvement is persistent.

Aged↗
PubMed1988

Asymptomatic episodes of ischaemia and their relation to heart rate changes in patients with chronic ischaemic heart disease.

The aim of our study was to evaluate the prevalence of asymptomatic episodes of ischaemia and their relation to heart rate in patients with effort angina pectoris undergoing continuous electrocardiographic monitoring for 24 h. We studied 91 patients with typical history of effort angina and positive stress testing (angina and rectilinear or downsloping ST segment depression more than 1 mm). During electrocardiographic monitoring 81 patients showed symptomatic or asymptomatic ischaemic episodes with ST segment depression, four patients a T wave inversion, while six patients did not show ischaemic episodes. The total number of ischaemic episodes registered was 284, of which 106 (37.32%) were symptomatic with significant heart rate increase, 130 (45.78%) asymptomatic with heart rate increase and 48 (16.9%) asymptomatic without heart rate changes. Twelve patients (13.18%) showed only symptomatic episodes of ischaemia with increase of heart rate, 26 patients (28.57%) symptomatic and asymptomatic episodes with heart rate enhancement, 12 patients (13.18%) only asymptomatic episodes with heart rate increase, eight patients (8.79%) symptomatic episodes of ischaemia with heart rate increase and asymptomatic ones with and without heart rate changes, and finally 23 patients (25.57%) showed symptomatic episodes with heart rate increase and asymptomatic ones without heart rate changes. In total, 31 (34.06%) of these patients showed during continuous electrocardiographic monitoring asymptomatic episodes of ischaemia without heart rate changes. These findings suggest a possible intervention of coronary tone modifications in determining asymptomatic ischaemic episodes without heart rate change in patients with effort angina.

Adult↗
PubMed1987

Ketanserin versus propranolol in the treatment of mild and moderate essential hypertension: corroboration with ambulatory blood pressure monitoring.

In order to assess the medium-term efficacy of ketanserin in comparison with that of the beta-blocker, propranolol, a randomized double-blind crossover trial was conducted involving 13 patients suffering from mild or moderate essential hypertension. Six of these patients were also evaluated on an ambulatory basis using noninvasive intermittent blood pressure monitoring to corroborate these values. Results indicated that both ketanserin and propranolol significantly lowered systolic, diastolic, and mean blood pressure levels after 60-day treatment periods. Diastolic blood pressure levels of less than or equal to 90 mm Hg were achieved in seven patients following ketanserin therapy and in six patients after treatment with propranolol. Both ketanserin and propranolol reduced arterial blood pressure without interfering with its circadian rhythm and variability. A tendency for the blood pressure lowering effect of ketanserin to increase with age was also noted. Side effects were minimal. The results of this trial confirm the efficacy and safety of ketanserin for the treatment of mild or moderate hypertension.

Adult↗
PubMed1986

Effects of ketanserin on ambulatory blood pressure monitoring in patients with essential hypertension.

Ketanserin is a new potent antiserotonergic drug which, unlike previous ones, is selective for S2-serotoninergic receptors and does not have an agonist action. A trial was carried out on medium-term treatment with ketanserin or propranolol in subjects suffering from mild to moderate hypertension. The trial was designed as a double-blind crossover randomized study comparing either ketanserin or propranolol with placebo. Thirteen patients completed the study, which was divided into two groups (A and B). Systolic (SBP), diastolic (DBP) and mean (MBP) blood pressures were measured by non-invasive, intermittent ambulatory monitoring performed using a Pressurometer II, from Del Mar Avionics. Heart rate was measured using a continuous electrocardiogram monitoring. Systolic blood pressure was significantly reduced both after ketanserin (A:11.1%; B:10.8%) and propranolol (A:11.7%; B:11.8%) but in group A its decrease was more pronounced after propranolol (P less than 0.01). Diastolic blood pressure was significantly reduced both after ketanserin (A:11.5%; B:11.1%) and propranolol (A:11.4%; B:11.9%), as was MBP (A:11.9%; B:11.8% for ketanserin and A:11.9%; B:11.9% for propranolol). The heart rate diminished significantly only after propranolol administration (P less than 0.01). Ambulatory monitoring showed a significant 24-h reduction of SBP after administration of propranolol (P less than 0.0025) and ketanserin (A:P less than 0.0025, B: P less than 0.005). Diastolic blood pressure was also significantly reduced after ketanserin (P less than 0.0005) and propranolol (A: P less than 0.0025, B: P less than 0.0005). The heart rate obtained by continuous electrocardiogram monitoring diminished significantly only after propranolol administration (P less than 0.0005). No significant changes of circadian behaviour of blood pressure were observed.

Adult↗