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Biomedical subjects

A Ferrari

Publications and source records attributed to A Ferrari.

At least 325 records · Page 18Linked to original sources
PubMed1981

Study of the long-term effects of selective biliary obstruction (SBO).

Selective biliary obstruction (SBO) is a model of partial cholestasis in the rat in which the bile duct draining the median lobe is ligated and transected; the remaining biliary tree remains intact. Other authors introduced this experimental model and studied morphological and biochemical modifications in the liver after 2 days from surgery. They suggest that an adaptation may occur. Choosing some markers of cholestasis and some other markers of various cytoplasmic organelles, we studied the long-term effects that occur in serum and in total liver homogenate of selectively obstructed rats as compared to controls. Alkaline phosphatase activity and bile acids content, which were significantly higher than controls in serum and in total liver homogenate of the median lobe after 2 and 8 days from SBO, returned to normal range values after 30 days. Cytochrome-oxidase and glucose-6-phosphatase activity in total homogenate of the SBO median lobe remains perfectly similar to the control values in time. Results, together with morphological observations, suggest that cholestasis is present immediately after operation, then decreases gradually and disappears finally. The obstructed median lobe seems to cope with cholestasis.

Alkaline Phosphatase↗
PubMed1981

Carotid sinus reflex control of renin release in hypertensive subjects with high renin secretion.

1. Carotid baroreceptor manipulation (neck-chamber technique) and passive head-up tilting were used in ten patients with renovascular hypertension and in five subjects with essential hypertension under diuretic treatment to study reflex control of renin secretion at high basal-renin production rates. 2. Reflex effects of carotid baroreceptor manipulation on renin secretion were only minor. During baroreceptor deactivation there was a moderate increase in mean arterial pressure, but an inconsistent change in the renal venous--arterial difference in plasma renin activity (PRA). 3. During baroreceptor stimulation there was a modest fall in mean arterial pressure and a marked rise in the renal venous--arterial difference in PRA. This was opposite to the fall which might have been predicted as a result of the sympathetic depressor influence of the baroreceptor stimulus. Conversely, tilting increased the venous--arterial PRA difference by about 200%. 4. It is concluded that when renin production rate is high carotid baroreceptors exert little control over renin release, just as when renin production is low. Reflex control of renin, however, is very active in subjects with a high renin production, probably due to receptors in the cardiopulmonary region.

Adult↗
PubMed1981

Digitalis and baroreceptor reflexes in man.

Data in animals indicate that large amounts of digitalis potentiate arterial baroreflexes and that this factor may be important for the cardiovascular effects of the drug. To determine if arterial baroreflex potentiation also exists after administration of therapeutic doses of digitalis in man, we studied how stimulation and deactivation of arterial baroreceptors by phenylephrine and nitroglycerin injection affect heart rate and how stimulation and deactivation of carotid baroreceptors by neck suction and pressure affects blood pressure and heart rate. The study was performed in 29 normotensive or hypertensive subjects before and after injection of Lanatoside C (0.8 mg i.v.). Baroreceptor stimulation reduced heart rate and blood pressure, while baroreceptor deactivation increased both of these variables. The bradycardic and hypotensive effect of baroreceptor stimulation increased significantly after digitalis both in normotensive and hypertensive subjects. However, the tachycardic and hypertensive responses to baroreceptor deactivation were not affected by digitalis. Thus, therapeutic doses of digitalis in man enhance baroreceptor reflexes, and both the heart rate and the blood pressure reflex effects are involved. However, the enhancement occurs to a marked degree only with baroreceptor stimulation and is not evident with baroreceptor deactivation.

Adult↗
PubMed1981

[Clinical usefulness of thallium-201 myocardial scintigraphy with dipyridamole pharmacodynamic test in ischemic heart disease (author's transl)].

A clinical evaluation of the dipyridamole in the myocardial perfusional scintigraphy (MPS) was carried out in a series of patients, comprehensive of cases of unstable angina, aiming to assess the feasibility and diagnostic validity of the test and to state its possible role in comparison with exercise stress test. On the whole, 107 subjects were examined (34 with stable angina, 23 with unstable angina, 19 with recent myocardial infarction, 15 with atypical angina, 10 with chest pain of uncertain origin and 6 healthy volunteers), performing 108 scintigraphic studies (48 after dipyridamole infusion and 37 after bicycle exercise). In the studies with physical or pharmacologic stress a redistribution scintigraphy was also performed (4 hour after the injection). The dipyridamole stress test was well tolerated by patients with unstable angina too and showed a diagnostic sensitivity equivalent to that with exercise stress, although the latter appears better as regards image quality and can give an increase of sensitivity provided electrocardiographic findings are evaluated. Post-stress redistribution of 201 Tl in delayed scans was shown either after dipyridamole or after exercise in patients with typical angina without prior infarction. The computation, by the Bayes's theorem, of the predictive value of the two tests leads the Authors to the following conclusions: in atypical angina (prevalence of CAD: about 40%) the association MPS + exercise ECG is preferable; in patients with chest pain of uncertain origin or with asymptomatic electrocardiographic alterations (prevalence of CAD: about 15%) it is better to take into account only the scintigraphic findings obtained after exercise or pharmacologic stress, to avoid an excess of false positive results.

Angina Pectoris↗
PubMed1981

The significance of the stop test in female urinary incontinence.

One hundred twelve cases of female urinary incontinence were studied. The bladder was stable in 53 patients and detrusor instability was detection in 59 of the incontinent women. Cystometry performed in the supine position cannot be relied upon to be sufficiently useful in the complete evaluation of various forms of instability. Involuntary detrusor contractions occurring during one or more provocative tests represent an abnormal bladder behavior pattern. An isometric contraction develops when the stream is interrupted and stable incontinent women show only a small isometric rise in 35 cases (66%). Fifty-six patients with unstable bladders presented a large isometric detrusor contraction (95%). Urodynamic studies combined with voiding stop tests can increase the clinical information of female urinary incontinence.

Adolescent↗
PubMed1980

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

Adult↗
PubMed1980

[Diabetic cardiomyopathy in preclinical phase. Polycardiographic and echocardiographic study (author's transl)].

Eighteen selected diabetic patients, without symptoms or signs of cardiac diseases and a control group of 15 normal subjects, age and sex matched, underwent polycardiographic and echocardiographic study, with the aim to evaluate their systolic and diastolic function of the left ventricle. PEP, LVET and PEP/LVET ratio were determined on the polycardiographic tracings. In eleven diabetic patients these data were also determined after amyl nitrite inhalation. Left ventricular diastolic dimension (DD), LV systolic dimension (DS), ejection fraction (EF), VCF, fractional shortening (FS), mitral opening delay (MOD) and the relaxation speed of the left ventricular posterior wall were determined on the echocardiographic tracings. All these data underwent statistical analysis by Student test, and some significant differences were found between diabetic patients and normal subjects. The mean value of PEP was augmented (diabetic patients: 100 +/- 18 msec; normal subjects: 88 +/- 9 msec; p 0,05), while the mean value of LVET was diminished (diabetic patients: 275 +/- 22 msec; normal subjects: 300 +/- 23 msec; p less than 0,005); the PEP/LVET ratio was, therefore, increased in diabetic patients (diabetic patients: 0,37 +/- 0,08; normal subjects: 0,29 +/- 0,04; p less than 0,005). Of all echocardiographic data only MOD (diabetic patients: 54 +/- 31 msec; normal subjects: 14 +/- 21 msec; p less than 0,001) was significantly increased in diabetic patients. The feasibility and reliability of polycardiographic and echocardiographic techniques in detecting early myocardial disfunction is discussed and the accurate selection of patients in order to exclude other myocardiopathies in pointed out. It is then concluded that diabetic patients, in comparison with normal subjects, show an impairment of both systolic and diastolic function of the left ventricle, exclusively depending on diabetes.

Adolescent↗