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Biomedical subjects

M Baroni

Publications and source records attributed to M Baroni.

At least 55 records · Page 3Linked to original sources
PubMed1993

Left ventricular remodeling in chronic aortic regurgitation.

Left ventricular (LV) shape in chronic volume overload due to aortic regurgitation is commonly described as rounder than in normal subjects. This statement derives from observations of qualitative nature or based on the measure of eccentricity index. We analyzed LV shape and function in 16 normal subjects (N) and in 24 patients with chronic pure aortic regurgitation (AR), without coronary artery disease or associated mitral regurgitation. LV cavity geometry was quantitatively evaluated from end-diastolic and end-systolic outlines obtained in 30 degrees RAO angiographic projection, by calculating: 1. the eccentricity and circularity indexes, 2. the regional curvature at 90 equidistant points using a windowed Fourier series approximation of contours, in which the number of harmonics and filter-window were locally chosen in order to minimize the reconstruction errors and to maximize the smoothness of the curve, 3. by measuring the length of the anterior and posterior hemi-perimeter of LV outlines and 4. by performing a Fourier analysis of LV contours. Neither eccentricity nor circularity indexes were adequate to differentiate shape abnormalities, whereas Fourier geometric analysis indicated abnormalities of shape in AR. Regional curvature showed that diastolic outline of AR had a greater curvature of the anterobasal, anterolateral and inferoapical regions and a lower curvature of the anteroapical one. Systolic outline showed a greater curvature of the inferoapical region and a lower curvature of the anteroapical one.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Steroid receptor enhancement by natural interferon-beta in advanced breast cancer.

In the current study we investigated the effect of two different doses of natural interferon-beta (IFN-beta) on steroid hormone receptors in 45 patients with advanced breast cancer. IFN-beta seems to regulate the receptor mechanisms, inducing in cutaneous metastases an increase of oestrogen and progesterone receptors. Moreover, using IFN-beta and tamoxifen as a combined therapy in 23 receptor-positive patients, no negative interference of the two drugs was observed and no relevant side-effects due to the treatment were noticed. The modulation of steroid receptor content by IFN-beta in advanced breast cancer might represent an interesting way to ameliorate the clinical responsiveness to anti-oestrogens.

Aged↗
PubMed1993

Effects of positive inotropic stimulation (post-extrasystolic potentiation) on non-uniformity of left ventricular contraction in patients with coronary artery disease.

In patients with chronic coronary artery disease, post-extrasystolic potentiation (PESP) slightly worsens relaxation, increasing the constant tau of ventricular pressure decay. However, it does not negatively influence left ventricular (LV) diastolic filling. To our knowledge, no data are available on the effects of PESP on segmental relaxation in chronic coronary artery disease. The effects of PESP on the LV pressure-volume (P/V) relationship and on segmental pressure-length loops (P/L) were studied in eight patients with coronary artery disease submitted to LV angiography. P/V loops were constructed by means of frame-to-frame analysis of ventriculograms and simultaneous high-fidelity LV pressure tracings; P/L loops were calculated by the endocardial movement of 45 chords intersecting the LV outline (centreline method). PESP was produced by programmed stimulation during ventriculography. P/V and P/L loops were studied in basal conditions and after PESP.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Prognostic value of the dipyridamole echocardiography test performed early after aortocoronary bypass surgery.

It has been demonstrated that high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography stress testing is feasible even in the first few hours after coronary artery bypass graft surgery and can be used to assess the beneficial physiological effects of coronary revascularization as well as graft patency. The aim of this study was to assess the role of dipyridamole echocardiography testing performed shortly after myocardial revascularization in the stratification of prognosis during follow-up. We studied 49 consecutive patients (45 males and 4 females; mean age 56 +/- 8 years) referred to our institute for elective myocardial revascularization. Six patients had single, 14 double, and 29 triple vessel disease. Forty-two left internal mammary artery grafts, 16 sequential venous grafts, and 45 single venous grafts were performed. All patients were submitted to dipyridamole echocardiography testing before (range 1-3 days) and shortly after (range 5-7 days) myocardial revascularization, always with the patients off antianginal medication. An arbitrary wall-motion score grading from 0 to 3 (normal, hypokinesia, akinesia, and dyskinesia) was applied to the seven regions into which the left ventricle was divided. Before surgery 48 patients showed wall-motion abnormalities during the test (47 patients also presented ECG changes). Angina occurred in 48 patients. One patient had ischemic ECG changes and angina. The mean wall-motion score was 3.11 per patient before and 6.5 per patient after the test (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Plasma steroid transport in subjects with tumors of hormonal target organs: a review.

Tumors derived from a hormonal target organ are assumed to be stimulated by the same hormone that stimulates the normal target tissue. In spite of attempts to acquire direct indications of a correlation between hormones and cancer, none have been definitive because studies of total and free hormone levels have given contradictory results. For this reason, attention has shifted to the study of plasma binding and transport of hormones, that is, of the proteins responsible for modulation of the hormone effect and thus of hormone bioavailability. The data reviewed indicate that in-depth study of the transport and binding system of sex steroids would give new information about the endocrine characteristics of cancer patients.

Breast Neoplasms↗
PubMed1992

Myocardial vitamin E is consumed during cardiopulmonary bypass: indirect evidence of free radical generation in human ischemic heart.

Although a role for free radicals in myocardial damage during cardiopulmonary bypass for open heart surgery has been postulated, direct evidence of free radical production as well as consumption of tissue antioxidants such as vitamin E is still lacking. Twenty patients (age 26-66 yr, mean 48) undergoing elective open heart surgery with moderate hypothermia, and cold crystalloid cardioplegia, were studied. Cardiopulmonary bypass time was 61.4 +/- 31.2 min. The specimens of atrial tissue collection before and after cardiopulmonary bypass, were immediately frozen in liquid nitrogen. Mean vitamin E atrial content, measured by reverse phase HPLC, was 355 +/- 249 pmol/mg of dry weight basally, 135 +/- 85 pmol/mg (p < 0.05) at the end of the ischemic period and 405 +/- 288 pmol/mg after the reperfusion period (p < 0.01). Microscopic examination of right atrial biopsies ruled out differences in fibrosis or cellular damage as the cause of vitamin E changes. Although a great basal variability in atrial vitamin E content was observed, which was independent of age, sex and clinical status, a reproducible and substantial decrease in atrial vitamin E content after cardiopulmonary bypass occurred (mean reduction 45 +/- 17% and 55 +/- 22%, respectively, after ischemia and after reperfusion). This was directly related to the aorta cross-clamping duration and partially to the minimum temperature achieved. In conclusion, apart from the great variability observed in basal vitamin E tissue content, vitamin E was always reduced during cardiopulmonary bypass, suggesting an oxidative stress on the myocardium during open heart surgery.

Adult↗
PubMed1992

Breast carcinoma and skeletal formation.

We have studied skeletal structure in 67 women with breast carcinoma and in 59 women without breast carcinoma, looking for differences of development that might be correlated with hormonal, metabolic or genetic abnormalities. We have measured the lengths of the limbs and of their segments (upper arm, forearm, thigh, leg), of the bisacromial and bitrochanteric transverse diameters and total height and height divided into the parts from vertex to pubis and from pubis to the ground. The analysis showed statistically significant coefficients of regression with presence of mammary carcinoma for height (0.0904262, S.D. 0.0461), length of thigh (0.12989, S.D. 0.03981) and length of lower leg (-0.68475, S.D. 0.1390). This skeletal type might be the expression of a genetic condition that is associated with the existence of mechanisms that permit development of mammary cancer.

Adult↗
PubMed1992

High dose aprotinin to reduce blood loss in patients undergoing redo open heart surgery.

Recently, aprotinin has been demonstrated to be effective in reducing post-operative bleeding after open heart surgery. The aim of this study was to evaluate the effectiveness of high dose aprotinin in patients undergoing redo open heart surgery in whom perioperative bleeding is generally increased. Fifty-eight patients, mean age 55 years, underwent a second open heart surgery for single valve replacement in 37 patients (mitral or aortic), for double valve replacement in 16 patients and for coronary artery by-pass grafting in 4 patients. In 30 of the 58 patients (Group A) aprotinin was infused with the following scheme: 2 million KIU in 30 minutes during induction of anesthesia, 2 million KIU in the priming volume of extracorporeal circulation and 500,000 KIU every hour until the end of the surgical procedure. The remaining 28 patients served as control group (Group B). No adverse reactions to aprotinin were observed. There was no significant difference in cardiopulmonary by-pass time and minimum temperature achieved between the two groups of patients. During the operative day blood loss was significantly lower in group A than in group B (492 +/- 336 ml vs. 628 +/- 273 ml) (p < 0.01). This difference was not significant during the following days. However 3 days after the operation a still significant difference was reported in total blood loss between group A and group B (816 +/- 507 ml vs. 1018 +/- 373 ml) (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Analysis of regional kinetics of the left ventricle by integration of morphologic data].

Regional left ventricular (LV) curvature analysis is a useful tool to assess the pathomorphological changes in LV shape which occur in different heart diseases. As LV shape changes follow regular trajectories, we used the curvature extrema and the normalized curvature variations as the features for identifying the movement of the borders during the cardiac cycle (curvature-motion method: CM). The regional curvature was calculated using a windowed Fourier series approximation of contours, in which the number of harmonics and filter-window were locally chosen in order to minimize the reconstruction errors and to maximize the smoothness of the curve. Analysis programs were tested on a series of ventricle-shaped contours, software generated. Left ventricular diastolic and systolic outlines obtained from RAO 30 degrees LV angiography in 24 patients with aortic insufficiency and in 16 subjects without heart disease were analyzed. Left ventricular curvature and regional wall motion were calculated in each subject. In respect to normal subjects, LV shape in aortic regurgitation definitely appears asymmetric because of the elongation of the anterior hemiperimeter and the prevailing expansion of the apical and anterolateral regions. These alterations in cavity geometry correlate to the decrease in pump function. According to these results wall motion analysis using the CM showed a greater extension of LV asynergy, while usual methods as the centerline or the radial one indicate a greater damage of the apical regions. Thus, the CM method seems to be a promising tool for wall motion analysis.

Angiocardiography↗
PubMed1991

5-Fluorouracil, epirubicin and cyclophosphamide (FEC combination) in advanced breast cancer.

Thirty patients with advanced breast cancer, not pretreated with chemotherapy for advanced disease, received a polychemotherapy regimen containing 5-fluorouracil (500 mg/m2 iv), epirubicin (50 mg/m2 iv) and cyclophosphamide (500 mg/m2 iv) every four weeks. All patients were evaluable for response and for toxicity. No complete remissions were observed, while 13 patients (43.5%) achieved a partial remission for a median duration of 46 weeks. The main side-effects were alopecia (grade 2-3 in 57%), leukopenia (grade 3-4 in 33%) and nausea/vomiting (grade 3-4 in 27%). In three cases we observed laboratory signs of cardiotoxicity without clinical symptoms.

Adult↗
PubMed1991

[Significance of the degree of oxidative hepatic metabolism in conditioning the pharmacokinetics and the pharmacodynamics of propafenone].

The aim of this study was to evaluate plasma concentrations of propafenone (P) and 5-hydroxy-propafenone (5-OH-P) at steady state in 36 patients with ventricular premature beats, Lown class greater than or equal to 2, submitted to antiarrhythmic treatment with propafenone either in acute administration (AA) (300-450 mg) or in chronic administration (CA) (150-300 mg t.i.d. for 14-21 days followed by a wash out), and to define the relationship existing between metabolic oxidative capacity and P and 5-OH-P pharmacokinetics and pharmacodynamics. Antiarrhythmic treatment resulted efficacious in 31/36 cases (86%) during AA and in 28/36 cases (78%) during CA. At steady state a wide interindividual variability was observed in plasma concentrations of P (mean = 835 +/- 619 ng/ml, coefficient of variation = 74%), in plasma concentrations of 5-OH-P (mean = 142 +/- 93 ng/ml, coefficient of variation = 65%) and of their ratio (mean = 6.51 +/- 8.53, coefficient of variation = 131%), without significant differences between responders and nonresponders. In a subgroup of 14 subjects, characterized as extensive oxidizers of dbrisoquine, a significant correlation (r = 0.97, p less than 0.001) was observed between the ratio of P and 5-OH-P plasma concentrations at steady state and oxidative metabolic capacity (expressed as debrisoquine/4-hydroxy-debrisoquine ratio). Oxidative metabolic capacity was also correlated with P half life (r = 0.82, p less than 0.002 in AA and in CA) and with the ratio of P and 5-OH-P area under curve (r = 0.91, p less than 0.001 in AA and r = 0.90) changes at the electrocardiogram (mean values = + 20% for QRS, +26% for PR). In conclusion, oxidative metabolic pathway is a crucial point in propafenone metabolization; indeed the extent of metabolic oxidative capacity, evaluable by analysis of debrisoquine oxidation, is responsible for a wide interindividual variability of P and 5-OH-P plasma concentrations, present even in a population of debrisoquine extensive oxidizers and, moreover, influences the extent of electrocardiographic changes of PR and QRS intervals, which are related to 5-OH-P plasma levels, but not to P plasma levels.

Adult↗
PubMed1991

Role of dipyridamole-echocardiography test in the evaluation of coronary reserve after coronary artery bypass grafting.

The object of this study was to assess the usefulness of the dipyridamole-echocardiography test in the early evaluation of coronary artery bypass grafting, when the use of an exercise stress test is precluded. We studied 39 consecutive patients (37 men and two women, mean age 57.3 years) referred to our institute for elective coronary artery bypass. Five patients had single, 12 patients double, 20 patients triple vessel disease, and two had left main stem disease. Nineteen left internal mammary artery grafts, 20 sequential grafts, and 39 single vein grafts were performed. All the patients were subjected to the test before (time range 1 to 3 days) and after (time range 6 to 10 days) the operation in the absence of therapy. Dipyridamole was administered intravenously 0.56 mg/kg over 4 minutes (low dose); if no effect was apparent, an additional 0.28 mg/kg over 2 minutes (high dose) was given. During the test, blood pressure and a twelve-lead electrocardiogram were monitored. An arbitrary wall motion score was derived by dividing the left ventricle into six regions and grading from 0 to 3-normokinetic, hypokinetic, akinetic, and dyskinetic zones. Preoperatively the test was positive in 38 patients as evidenced by wall motion abnormalities (36 patients had electrocardiographic changes) and in one patient by electrocardiographic changes and chest pain; 22 tests were positive after the low dose and 17 after the high dose. Angina was present in 33 patients. Mean wall motion score was 1.64 per patient in the basal condition and 4.03 per patient after the test (p less than 0.001). After coronary bypass in three patients the test was positive at the same dosage that was used preoperatively, as shown by wall motion abnormalities (in two patients by electrocardiographic changes, as well). Four patients had symptoms. Furthermore, at 6 months' follow-up, a treadmill stress test performed in these three patients was positive for ischemia and angina. The wall motion score was 1.25 per patient in the basal condition and 1.53 per patient after the test (no significant difference). When the preoperative wall motion score obtained after dipyridamole echocardiography was compared with the postoperative score, a statistically significant difference was seen: 4.03 per patient versus 1.53 per patient (p less than 001). In eight patients we observed an improvement of basal myocardial contractility after the operation, which indicates the reversibility of wall motion abnormalities observed before coronary bypass. In conclusion our data show that the dipyridamole-echocardiography test is a suitable method for the early assessment of bypass grafting when other methods, exercise dependent, are not indicated.(ABSTRACT TRUNCATED AT 400 WORDS)

Angina Pectoris↗
PubMed1990

Early assessment of coronary reserve after bypass surgery by dipyridamole transesophageal echocardiographic stress test.

The evaluation of coronary reserve within a few hours of aortocoronary bypass surgery could be of extreme utility for the follow-up or therapeutical management of these patients. In 11 men patients who underwent aortocoronary bypass surgery, a dipyridamole echocardiography stress test was carried out before (1 to 3 days), early after (68 to 130 minutes), and 1 week after surgery. The first and third tests were performed using a standard transthoracic approach, while the second was performed by a transesophageal approach. Dipyridamole was administered intravenously at a dose of 0.56 mg/kg body weight (low dose) and eventually adding 0.28 mg/kg body weight (high dose), always in the absence of antiischemic therapy. An arbitrary wall motion score (0 = eukinesia; 1 = hypokinesia; 2 = akinesia; 3 = dyskinesia) was assigned to the seven different myocardial regions in which the left ventricle was divided in order to have a semiquantitative score. Under basal conditions wall motion score per patient in the three series of tests did not change significantly (1.6, 1.4, and 1.5, respectively), while the mean score during dipyridamole administration showed significant differences (3.6, 1.9, and 1.9, respectively), indicative of the results obtained by surgical repair. The test, positive in all patients before surgery, showed wall motion abnormalities and ischemic ECG changes in two patients immediately after surgery by the transesophageal approach. One patient who had a normal basal contraction pattern and an abnormal response after the test developed in the following days a perioperative myocardial infarction, while a second patient in the follow-up period developed low-level effort angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Hyperkinetic ventricular arrhythmia during the treadmill test in chronic ischemic heart disease].

Aim of this study was to evaluate the pattern of onset and the characteristics of ventricular arrhythmias (VA) observed during treadmill test (TT) in patients with chronic ischemic heart disease (CIHD). Two groups of patients with CIHD were retrospectively compared: group A consisted of 120 consecutive patients with premature ventricular beats (PVBs) either isolated (greater than 2/min) or repetitive during exercise, or maximal exercise, or recovery; group B consisted of 140 consecutive patients without PVBs during TT. The two groups were comparable in mean age, male/female ratio, incidence of previous myocardial infarction, of previous coronary artery by-pass graft or of percutaneous transluminal coronary angioplasty. There were no significant differences between the two groups regarding the parameters evaluated during TT: duration of exercise, maximal heart rate, heart rate-systolic blood pressure product as well as in the percentage of positive tests for acute myocardial ischemia (51.6% vs 40.7%). In the two subgroups of patients who underwent coronary arteriography and left ventricular angiography (24/120 and 23/140 patients respectively) no differences were found in the number and distribution of critical coronary stenosis and of dyskinetic or akinetic areas. In both groups A and B the QTc interval at maximal exercise was significantly longer than its value at rest (p less than 0.001), but there was no relevant difference between the two groups. In group A patients with VA during maximal exercise (n = 60) showed a higher prevalence of complex VA (class Lown greater than or equal to 3) compared to the others (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1990

[Cardiac involvement in HIV infection: a prospective, multicenter clinical and echocardiographic study].

Cardiac abnormalities are frequently reported in patients with acquired immunodeficiency syndrome (AIDS). Much less is known about the true prevalence of cardiac involvement in patients with human immunodeficiency virus (HIV) infection. We prospectively examined 138 consecutive patients with HIV infection including 41 with AIDS, 49 with AIDS-related complex (ARC), 32 with chronic lymphoadenopathy syndrome (LAS) and 16 with asymptomatic HIV infection. Sixty-one patients had opportunistic infection. The prevalence of cardiac involvement progressively increased from patients with HIV infections or LAS (4%) to ARC (14%) to AIDS (37%). "Major" echocardiographic abnormalities (dilated cardiomyopathy and/or infective endocarditis and/or severe pericardial effusion) were identified in 3 patients (2%), "minor" abnormalities (mild pericardial effusion, hypokinesis of the interventricular septum, mild dilatation of the left ventricle in 21 (15%). Electrocardiographic abnormalities unassociated with echo abnormalities or clinical problems were seen in other 11 patients. End diastolic left ventricular dimension (normalized for body surface area) was higher among AIDS respect to pre-AIDS patients (30.1 +/- 7.1 vs 27.6 +/- 7.5; p less than 0.01) and among patients with respect to patients without opportunistic infections (29.5 +/- 6.5 vs 27.5 +/- 2.4; p less than 0.05). Left ventricular shortening fraction was lower in the subgroup with and absolute CD4 lymphocyte count less than 100/mm3 (31 +/- 7 vs 34 +/- 5; p less than 0.055). In conclusion, in a large, unselected group of patients with HIV infection, echocardiogram discloses cardiac abnormalities in 17% of the cases; their clinical relevance is generally low but in selected patients cardiac tamponade and/or dilated cardiomyopathy (secondary to viral myocarditis) may cause death.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗