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Biomedical subjects

S Lenzi

Publications and source records attributed to S Lenzi.

At least 55 records · Page 3Linked to original sources
PubMed1984

Evaluation of the effects of catheter sampling for the study of platelet behavior in the pulmonary and coronary circulation.

To study the effects of sampling through cardiac catheters on indices of platelet function, we measured the levels of platelet factor 4 (PF4), beta thromboglobulin (BTG), and platelet aggregate ratio (PAR) in 10 patients with atrioventricular accessory pathway (AVNAP), six patients with primary pulmonary hypertension (PPH), and six patients with critical narrowing of the left anterior descending artery (LAD). In AVNAP and LAD patients samples were drawn simultaneously from a peripheral vein, coronary sinus, and brachial artery; in AVNAP patients samples were also obtained from the axillary vein before the coronary sinus was entered. In PPH patients samples were drawn from pulmonary artery, aorta, and a peripheral vein; in these patients the effects of an intravenous infusion of prostacyclin (PGI2) (2 to 8 ng/kg/min) on PF4, BTG, and PAR were also studied at all sampling sites. In all patients arterial, coronary sinus, pulmonary arterial, and axillary venous levels of PF4, BTG, and PAR significantly exceeded those measured in the peripheral vein. PGI2 infusion resulted in a significant decrease of PF4 at all sampling sites, while no consistent BTG changes were observed and PAR levels did not decrease in the peripheral vein. Although a considerable interpatient variability in PF4 levels was observed, a significant (r = 0.91) correlation was found in patients with AVNAP between simultaneous coronary sinus and arterial PF4 levels. The value of PF4 coronary sinus-arterial difference in LAD patients was consistently higher than that calculated in AVNAP patients (54.5 +/- 28.9 vs 4.2 +/- 3.8 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Catecholamine release in coronary sinus during vasospastic angina induced by ergonovine.

In seven patients with spontaneous angina and three control subjects, aortic and coronary sinus norepinephrine and epinephrine were assessed. Samples were taken in basal conditions and during ergonovine test in coronary sinus and aorta. The behaviour of some hemodynamic parameters as heart rate, blood pressure, left ventricular end diastolic pressure and coronary sinus flow was also studied. Resting myocardial norepinephrine and epinephrine flux was similar for both groups. In ischemic patients ergonovine induced a coronary spasm accompanied by an evident reduction of coronary sinus flow and a slight increase in arterial epinephrine and norepinephrine concentrations. However, a significant decrease in the net myocardial norepinephrine and epinephrine release was evidenced. After ergonovine, not significant changes in norepinephrine and epinephrine concentration and release resulted in control subjects. The increase in peripheral catecholamine concentrations found in ischemic patients during ergonovine test could represent a reflex activation of sympathetic activity induced by an ischemia dependent ventricular mechanical disfunction. The decrease in myocardial catecholamine release during angina could be justified by sequestration of epinephrine and norepinephrine in ischemic areas induced by vasospasm or reflex inhibition of cardiac sympathetic tone.

Adult↗
PubMed1983

[The Brisighella survey: a study of dietary habits].

In the course of studies evaluating diet as risk factor of atherosclerotic disease, an epidemiological study among 1491 males and 1448 females living in Brisighella, a small village in the Tuscan-Emilian Appenines, was carried out. The methods used in estimating alimentary habits have been described in detail. The weights of all foods eaten by each subject in a 7 day period were also recorded. We considered total intake of proteins, fats and carbohydrates in g/kg of ideal weight/day and total calories/kg of ideal weight/day and related such values to those given by FAO/WHO. It was observed that mean intake of proteins and fats in g/kg/day and cal/kg/day was always more elevated when compared with those given by FAO/WHO for males and females. Mean intake of carbohydrate, in both sexes, agreed with FAO/WHO values. Therefore, we can affirm that the people of Brisighella have faulty dietary habits, mainly concerning fats. In addition, their daily calorie-intake is too high.

Arteriosclerosis↗
PubMed1982

[Myocardial infarct: an acute dysmetabolic disease].

It is hypothesised, on the basis of experimental observations on post-heparin plasma samples collected under post-prandial conditions, that variations in the activity of endothelial lipoproteinlipasic systems may be correlated to reductions in blood flow at coronary capillary level. More specifically, it is shown that a change in these enzymatic systems could determine "functional kidnapping" of heparin or other substances (glicosaminoglycans) engaged in the activation of Antithrombin III, with noteworthy haemorrheological consequences mediated by a variety of mechanisms. Relations between such haemorheological and metabolic changes further to activation of lipoprotein lipase are discussed and stress is laid on the importance both might have in the pathogenesis of myocardial infarction.

Adult↗
PubMed1982

Hemodynamic and metabolic effects of nitroglycerin ointment in pacing-induced angina pectoris.

Hemodynamic and metabolic effects of nitroglycerin ointment (40 mg nitroglycerin) were tested on 15 patients with clinical evidence of stable angina. Basal value (B) and atrial pacing (AP)-dependent changes were evaluated before and 30 min after ointment administration. After treatment tension time index (TTI) basal value showed a 19% reduction (p less than 0.05). Compared to the control a lesser AP-dependent increase was also noted (27%, compared to 45%; p less than 0.005). According to TTI reduction, MVO2 showed an evident decrease both in basal conditions and during AP (21% and 29.6%, respectively). On the contrary, diastolic pressure time index (DPTI) does not result significantly influenced by the treatment. Consequently, DPTI/TTI ratio increase is largely the result of TTI reduction, which is well correlated to myocardial oxygen demand. Coronary sinus blood flow decrease (16% and 27% under basal conditions and during AP, respectively) confirms that the therapeutic efficacy of the ointment does not result from an increase in myocardial oxygen supply. Finally, during AP nitroglycerin ointment resulted in a significant decrease in myocardial lactate release (L% mean value ranges from-17.5% to 3.4%; p less than 0.001). Such an improvement probably reflects a primary influence of the drug on the extracoronary vascular bed.

Adult↗
PubMed1982

[Importance of metabolic disorders and endocardial viability ratio in the prognosis of open-heart operations. Experimental study of the pig heart protected by potassium cardioplegia in hypothermia].

The aim of this study was to investigate the protective efficacy of potassium cardioplegia in general moderate hypothermia, in five pigs, after 90 minutes of myocardial ischemia induced by extracorporeal circulation (ECC) and aortic clamping. The behaviour of subendocardial supply demand ratio (DPTI/TTI), of CSBF (coronary sinus blood flow) and numerous hemodynamic parameters was evaluated in addition to lactate myocardial metabolism changes, at rest, after 90 minutes of total ECC and during a 60 minutes reperfusion period. The reperfusion period included two phases: during the first (15-20 minutes) the animals were in ECC with unclamped aorta; spontaneous circulation was instituted during the second one (40 minutes). A marked increase in CSBF was observed at aortic clamp removal during the first phase (post ischemic reactive hyperemia). Coronary sinus lactate release was also noted, probably due to wash-out of previously sequestered acid metabolites during aortic clamping (90 minutes). At the onset of the second phase a depressed left ventricular performance and low DPTI/TTI values were shown. A rapid return (20 minutes) to normal values of this parameter was then noted. DPTI/TTI normalization results strictly correlated to the progressive improvement in myocardial performance. Hypothermic potassium cardioplegia seems therefore to prevent the irreversible myocardial damage and favour a fast recovery of cardiac function.

Animals↗
PubMed1981

[The Brisighella study. I. Non-metabolic risk factors].

The Brisighella Study, an epidemiological observational investigation on coronary heart disease risk factors was performed in a little Emilia-Romagna town with agricultural background. At entry, in 1972, 1,491 males and 1,448 females were enrolled from the residents of the inner part of the town. The participation response was very high (93%). In this paper the smoking habits and physical activity are reported. The prevalence of smoking habits was 51.8% in males, quiet different from the female group (24.5%). Heavy smokers were more frequently observed in young people, than in the oldest female groups. The physical activity mean levels were very low both in males and in females and the prevalence of heavy physical activity during leisure time was very low, especially in the woman.

Adolescent↗
PubMed1981

[The Brisighella study. II. Metabolic risk factors].

The Epidemiological Study of Brisighella, a rural little town of Emilia-Romagna, started in 1972. At entry 1448 females and 1491 males, aged 14-84 years, were examined. In this paper the mean values of Total Serum Cholesterol (TC), Triglycerides (TC), Serum Uric Acid (SUA) and Fasting Blood Sugar (FBS) for age classes and sex, were described. This values were for all males, of 222.6 mg/dl (TC), 153.0 mg/dl (TG), 53.5 mg/dl (SUA) and 85.0 mg/dl (FBS). In the females the mean TC values were higher than in the males (226.2 mg/dl); the mean values of other parameters were lower: 129.1 mg/dl (TG), 83.3 mg/dl (FBS) and 47.0 mg/l (SUA).

Adolescent↗
PubMed1981

[The Brisighella study. III. Hypertension as a risk factor (author's transl)].

The Brisighella Study was performed in a little Emilia-Romagna town with agricultural background to observe coronary heart disease risk factors in this population. At entry, 1972, 1491 males and 1448 females were controlled from the residents of the inner part of the town. The participation response was very high (93%). In this study the hypertension evaluation as risk factor is reported. Measurement of blood pressure has been made in according to W.H.O. criteria. Blood pressure mean values, hypertension prevalence, borderline blood pressure prevalence and hypertension control level have been recorded. The male subjects with hypertension were 33.53%, while female subjects were 33.77%. Borderline blood pressure was higher in males than in females (32.0% vs. 25.7%). Hypertension control level in the examined sample was quite low, however, it appears higher than other reported in similar studies.

Adolescent↗
PubMed1979

Effects of indomethacin on postural hypotension in Parkinsonism.

A study was conducted to evaluate the effect of indomethacin on orthostatic hypotension in Parkinsonism. Twelve elderly patients participated and the drug was given in two-ways--as an intravenous infusion of 50 mg over 30 minutes and by mouth 50 mg thrice daily for six days. Results were assessed by measuring the degree of hypotension on standing, response to the cold pressor test, and forearm blood flow (by strain-gauge plethysmography). Indomethacin significantly reduced the fall in blood pressure on standing (P less than 0:001) and lessened or reversed orthostatic symptoms. Furthermore, there was an enhanced response to the cold pressor test and a reduction in forearm blood flow. These findings suggest that indomethacin has a positive effect on systemic vascular resistance.

Administration, Oral↗
PubMed1979

Study of the metabolic effects of bunitrolol (Koe 1366) in angina induced by catecholamine infusion.

In ten angina patients responding with a myocardial anaerobic metabolic pattern to isoproterenol infusion, a new beta-blocking agent, bunitrolol, was effective in normalizing the myocardial lactate extraction ratio. The correlation with lipid metabolism was also interesting because beta-blocker action reduced significantly arterial non-esterified fatty acids (NEFA) level as well as myocardial NEFA extraction. The metabolic behavior suggests the effectiveness of bunitrolol in the treatment of ischemic heart disease.

Angina Pectoris↗
PubMed1978

Blood lipids in Italy. Regional differences.

Serum cholesterol and triglyceride levels have been evaluated in samples from fasting males aged 20--59 in Northern (Brisighella), Central (Rome) and Southern (Pozzuoli) Italy. Regularly performed quality controls between laboratories assured comparability of data. A statisitically significant difference of mean serum cholesterol and triglyceride levels was observed for most age-groups in the 3 different areas, lower values being found in the southern population as compared to the central and northern ones. These results support previous findings and the thesis that large differences in blood lipid levels may still exist even within the same country and that they at least in part may be culturally determined in connection with different dietary habits.

Adult↗
PubMed1978

[The gamma-glutamyltransferase (GGT) isoenzymes in human serum (author's transl)].

With this report we communicate the results of a method for the fractionation of the isoenzymes of gamma-GT in human serum based on a modified technique of Hetland et al., using cellulosa acetate. With this method we observed the appearance of a complex of four band representing: gamma-GT1 = prealbumin-albumin, gamma-GT3 = alpha 1-globulin, gamma-GT3 = alpha 2-globulin, gamma-GT4 = beta-globulin. It has been noted that the gamma-GT2 is the only fraction which constantly appears. This isoenzyme also corresponds to the form, fisiologically present in serum and is presumably preduced in the cells of the bileduct. In the results we observed the appearance of gamma-GT1 only in the course of processes involving certainly cholestasis. This fraction was once reported by other AA., but it has an unknown origin. It was not possible to correlate the appearance of the fractions gamma-GT3 and gamma-GT4 with any specific pathology alterations even though Hetland et al. have affirmed that the gamma-GT3 band derives from hepatic parenchyma.

Gallstones↗
PubMed1978

[The antegrade GAPs (author's transl)].

GAP in a-v conduction is defined as a zone within the cardiac cycle where premature atrial impulses fail to evoke ventricular responses whereas atrial beats of greater and lesser prematurity do. This phenomenon occurs when the effective refractory period (ERP) of a distal site is greater than the functional refractory period (FRP) of a proximal site of the conduction system. To date, Damato and Co. classify antegrade gaps into six types on the basis of blocks location and proximal delay that permits conduction recovery: type I: HPS and AVN; type II: HPS (distal) and HPS (proximal); type III: HPS and His-bundle; type IV: AVN (distal) and AVN (proximal); type V: AVN or HPS and atrium; type pseudo-V: AVN or HPS and antrial miocardium proximal to stimulation site; type VI: HPS and supernormality (no proximal delay). The Authors propose, on the basis of 37 cases of GAP phenomenon observed in 185 electrophysiological studies, a new classification of antegrade gaps, which complete and partially modifies Damato's one. Tyes I-II-II-IV and V are divided into A and B forms according to the type and the site of the distal block. GAP type VI is replaced by Damato's pseudo-V. Two new types are proposed: in the first (type VII) the distal block is in the atrium and the proximal delay is in atrial miocardium proximal to stimulation site; in the second (type VIII), in subjects with pre-excitation, the block is in the accessory pathway and the proximal delay is in atrium.

Adolescent↗