PubMed Health⌕ Search

Biomedical subjects

M Bernardi

Publications and source records attributed to M Bernardi.

At least 19 recordsLinked to original sources
PubMed1992

The hemodynamic status of preascitic cirrhosis: an evaluation under steady-state conditions and after postural change.

To assess the hemodynamic status of patients with compensated cirrhosis, mean arterial pressure, cardiac index and peripheral vascular resistance and markers of central (plasma concentrations of atrial natriuretic factor) and arterial volemia (plasma norepinephrine concentration, plasma renin activity) were studied in 10 patients and 10 healthy control subjects under steady-state conditions (after 2 hr of standing) and after assumption of the supine position (30, 60, and 120 min). After standing, neither hemodynamics nor markers of effective volemia differed significantly between controls and patients. By evaluating the areas under the curve during the 2 hr of supine posture, the increase in cardiac output and plasma natriuretic factor and the decrease in peripheral vascular resistance were greater in patients (2.59 +/- 0.43 [S.E.M.] L/min/hr; 32.8 +/- 7.2 pg/ml/hr -1,103 +/- 248.4 dyn.sec/cm5/hr, respectively) than in controls (0.53 +/- 0.24 L/min/hr, p = 0.005; 17.4 +/- 4.7 pg/ml/hr, p = 0.005; -265.5 +/- 206.2 dyn.sec/cm5/hr, p = 0.02). The declines in heart rate, plasma norepinephrine concentration and plasma renin activity did not differ significantly. Mean arterial pressure did not significantly change. Our results suggest that during periods of upright posture, cirrhotic patients in the preascitic stage, who are known to have expanded blood volume, compensate for dilatation of the splanchnic vascular bed through total hypervolemia. The latter becomes excessive during recumbency, leading to supernormal increases in venous return, central volemia and cardiac index. The decline in peripheral vascular resistance appears to be a compensatory mechanism to maintain steady arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Natriuretic Factor↗
PubMed1992

Influence of CRF and alpha-MSH on the migration of human monocytes in vitro.

The effects of stress in the modulation of immune responses are increasingly reported by a rapidly growing body of experimental and clinical data. Here we show that corticotropin releasing factor (CRF) stimulates 'in vitro' the migration of human monocytes, the maximum effect being obtained at 10(-14) M. On the other hand, another important neuropeptide of the stress response, alpha-melanocyte stimulating hormone (alpha-MSH), has no significant effect on the migration of monocytes. These findings show that one of the oldest immune responses is directly modulated by a key mediator of the stress response.

Chemotaxis, Leukocyte↗
PubMed1992

Bed-rest-induced hypernatriuresis in cirrhotic patients without ascites: does it contribute to maintain 'compensation'?

Renal function, plasma renin activity, plasma aldosterone concentration and urine excretion of free norepinephrine were evaluated in 13 cirrhotics without previous or ongoing ascites and in 13 healthy subjects, after 6 days of controlled electrolyte intake (40 mmol of Na and 70 mmol of K per day) and during 24 h of recumbency. Plasma concentrations of the atrial natriuretic peptide (ANP) were also measured in 8 patients and 8 controls. Despite a low-normal filtered load of sodium (14.6 +/- 1.2 vs. 17.1 +/- 1.2 mmol/min), cirrhotic patients showed supernormal natriuresis (141.5 +/- 14.1 vs. 78.8 +/- 8.6 mmol/day; p < 0.001). Whereas the fractional excretion of sodium in these patients was twice that of controls (0.70 +/- 0.05 vs. 0.36 +/- 0.04%; p < 0.001), potassium excretion (42.5 +/- 2.7 vs. 43.1 +/- 2.7 mmol/day) and urine volume (1270 +/- 98 vs. 1452 +/- 148 ml/day) did not differ. In cirrhotics, plasma renin activity was reduced (0.50 +/- 0.12 vs. 1.39 +/- 0.33 ng/ml/h; p < 0.02), and plasma aldosterone concentration tended to be lower (66 +/- 10 vs. 86 +/- 9 pg/ml; p = 0.09), while urine norepinephrine excretion did not significantly differ from controls (961 +/- 120 vs. 782 +/- 43 ng/h). ANP was higher in patients than in controls (92 +/- 17 vs. 48 +/- 9 pg/ml; p < 0.05). Natriuresis was directly correlated with ANP (r = 0.69, p < 0.005) and ANP/plasma aldosterone ratio (r = 0.63; p < 0.01) in patients and healthy subjects taken together.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Can evoked phonomyography be used to recognize fast and slow muscle in man?

The present study is aimed at ascertaining if muscle sound might be used as a detector of the contractile properties of individual human muscles "in vivo". In order to test this hypothesis, Soleus muscle (slow) and Vastus Lateralis Femoris muscle (fast) were investigated in three healthy subjects during electrically elicited contractions. Evoked phonomyograms were obtained from isometric single twitch contractions using a microphonic apparatus. Time and frequency domain analysis were performed. Evoked phonomyogram rising time values obtained from the two muscles are significantly different (p less than .01) and this difference is clearly due to their different mechanical properties. The power spectrum of all signals was obtained by means of harmonic analysis routine and mean frequency thus obtained was taken into account. Power spectrum values are approximately 1.5 times greater in fast muscle than in slow muscle (p less than .01). These findings lead us to the conclusion that evoked phonomyography can be considered a useful technique for the assessment of mechanical properties of individual human muscles.

Adult↗
PubMed1979

Diuretic-induced renal impairment without volume depletion in cirrhosis: changes in the renin-angiotensin system and the effect of beta-adrenergic blockade.

In 4 patients with cirrhosis and ascites, diuretic therapy resulted in an impairment of renal function that was associated with a rise in plasma renin activity (PRA). In 3, this occurred in the absence of volume depletion. When diuretics were discontinued, renal function returned to normal. beta-adrenergic blocking drugs were then given to suppress renin secretion and diuretics restarted. On this occasion, impairment of renal function did not occur. In 2 further patients, administration of beta-adrenergic blockers during a period of diuretic-induced renal impairment resulted in an improvement in renal function. Although these findings may indicate that diuretic-induced renal impairment in cirrhosis is at least partly due to activation of the renin-angiotensin system, in another group of patients a diuretic-induced rise in PRA was not associated with a deterioration in renal function.

Adrenergic beta-Antagonists↗
PubMed1978

Validation of "transit renography" for the determination of the intrarenal distribution of plasma flow: comparison with the microsphere method in the anaesthetized rabbit and pig.

1. The spectrum of transit times of sodium o-iodohippurate (Hippuran) through the kidney can be derived from an 131I- (or 123I-) labelled Hippuran renogram by deconvolution. In the rabbit and pig, as has previously been shown in man, the frequency distribution curve for the transit times was bimodal. Since the transit time is likely to be proportional to the nephron length, the area of the first mode is likely to represent plasma flow to the shorter outer cortical nephrons whereas the delayed mode represents flow to the long juxtamedullary nephrons. 2. This interpretation was tested by simultaneously comparing renography with the microsphere method of measuring intrarenal plasma flow distribution in 12 rabbits and two pigs with a variety of anaesthetics. A close agreement was found between both methods for the percentage of plasma flow distributed to the outer cortical nephrons, thus supporting the use of "transit renography" to determine the intrarenal distribution of plasma flow.

Anesthetics↗
PubMed1978

Lymphocytotoxicity test against rabbit hepatocytes in chronic liver diseases.

We have studied the cytotoxicity against rabbit liver cells of lymphocytes from the peripheral blood of 71 patients with various liver diseases. The group with chronic active hepatitis and three patients with acute alcoholic hepatitis showed significantly higher mean values of lymphocytotoxicity (P less than 0.001) compared with the other patients with chronic persistent hepatitis, post-necrotic fibrosis and cirrhosis. Wilson's disease, and prolonged viral hepatitis. The mean cytotoxicity of these last groups did not differ significantly from controls. In four out of six patients with chronic active hepatitis a significant decrease of lymphocytotoxicity was found after immunosuppressive therapy with oral prednisolone. A good correlation between the lymphocytotoxicity test and histological signs of activity suggests that a cell-mediated immune aggression is present in this disease.

Adolescent↗
PubMed1977

Effect of beta adrenergic blocking drugs on the renin-aldosterone system, sodium excretion, and renal hemodynamics in cirrhosis with ascites.

As a result of effective beta adrenergic blockade with either propranolol or practolol, plasma renin activity was suppressed in all of 11 patients with cirrhosis and ascites. In contrast, the effect on the rate of renal excretion of aldosterone was variable, suggesting that factors other than the renin-angiotension system are responsible for the control of aldosterone secretion in cirrhosis. The changes in aldosterone could not be explained on the basis of changes in the plasma concentrations of potassium or sodium. The renal sodium excretion was inversely related to the values for aldosterone both before and after beta adrenergic blockade, indicating a major role for aldosterone in regulating sodium excretion. A number of patients had an abnormal intrarenal distribution of plasma flow with a relative hypoperfusion of the renin-secreting outer cortical nephrons. Plasma renin activity was inversely related to outer cortical plasma flow, suggesting that the reduced outer cortical flow may be a stimulus to increased renin secretion. Because the abnormal intrarenal hemodynamic pattern was not corrected by suppression of plasma renin activity, and presumably angiotension II concentrations, it is unlikely that it is attributable to the known renal vasonconstrictor effects of angiotensin II.

Adrenergic beta-Antagonists↗
PubMed1975

[Double-blind polycentric study of the action of S-adenosylmethionine in hepatic cirrhosis].

Two comparable groups of patients with hepatic cirrhosis of different genesis in a compensation phase have been treated for 30 days with S-adenosylmethionine and vitamine B-12 (28 cases) or with vitamine B-12 alone (25 cases). The drugs were given by slow intravenous route at the daily dose of 150 mg of SAMe and 2000 gamma of vit. B-12 or of 2000 gamma of vit. B-12 alone, in two adminstrations. An evaluation of the results was carried out mostly on the laboratory data testing the liver function. Only the group of patients who had received SAMe showed significant modifications of all the parameters considered. This is confirming SAMe ability to restore hepatocyte activity bringing also to normal the protein synthesis.

Aged↗