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Biomedical subjects

M Bardelli

Publications and source records attributed to M Bardelli.

At least 37 records · Page 2Linked to original sources
PubMed1992

Non-invasive ultrasound assessment of renal artery stenosis by means of the Gosling pulsatility index.

OBJECTIVE: To gauge the effectiveness of a new Doppler test for renal artery stenosis (RAS), based on the pulsatility index of the blood flow velocity spectrum within several interlobar arteries of both kidneys. METHODS: Twenty normotensive volunteers and 49 hypertensive patients were investigated with ultrasound. Patients with angiographic signs of RAS underwent bilateral renal vein catheterization for renin measurement. Significant RAS was assumed if lateralization of renal vein renin to the stenotic side was proven. RESULTS: The pulsatility index was higher in the hypertensives without RAS than in normal volunteers. Side differences between both kidneys were within methodological variations with the exception of one case, in whom side difference was > 0.12. The pulsatility index was lower in kidneys with significant RAS than in kidneys without RAS. In most patients with significant unilateral RAS the side difference was < 0.12. In the other patients with a low pulsatility index and a side difference < 0.12 RAS was found to be bilateral upon angiography. Doppler signals were absent in all kidneys with renal occlusion. CONCLUSIONS: A side difference of > or = 0.12 predicts unilateral RAS, whereas the absence of parenchymal Doppler signals indicate occlusive RAS. A low pulsatility index combined with normal side difference may, in hypertensive patients, indicate bilateral RAS. Renovascular hypertension was correctly diagnosed in 84% of the patients and the presence of RAS in 94%.

Adult↗
PubMed1991

An ultrasonographic method to measure the sensitivity of the baroreflex in clinical practice: application to pharmacological studies.

To determine whether it is possible to assess baroreceptor sensitivity by measuring changes in blood velocity in the carotid artery and changes in the heart rate, we performed a series of 108 experiments in 19 hypertensives aged 20-57 years (mean 46.6 +/- 8.6). In each experiment, we took simultaneous measurements of carotid artery blood flow velocity (Doppler technique), the brachial intra-arterial blood pressure and the heart rate, during a rapid and transient increase in blood pressure induced by injections of phenylephrine. We then calculated the maximum slope of the regression lines correlating blood velocity with the heart period (Trieste method) and blood pressure with the heart period (Oxford method). We obtained good accuracy from the Trieste method compared with the Oxford method, as assessed by the mean of the sum of the squares (difference + 5%, NS). After the administration of 4 mg oral lacidipine to 13 essential hypertensives, aged 37-54 years (47.6 +/- 5.3), baroreflex sensitivity was not changed, as assessed by either method (Oxford method 10.1 +/- 5.5 versus 9.8 +/- 6.2 ms/mmHg; Trieste method - 0.57 +/- 0.32 versus - 0.49 +/- 0.31 ms/Hz). The coefficients of variation for the two methods, calculated for the measurements taken before and after the administration of lacidipine, were not statistically different (Oxford method 25.0 +/- 18.4 versus 36.2 +/- 16.0; Trieste method 36.7 +/- 19.2 versus 39.7 +/- 19.2). The new non-invasive Trieste method thus showed the same accuracy and precision as the invasive Oxford method in measuring baroreflex sensitivity and can be used in pharmacological studies.

Antihypertensive Agents↗
PubMed1991

[Ledderhose's disease].

The authors describe the clinical appearance of Ledderhose disease and emphasize the association with Dupuytren disease. They report on a series of patients treated at the 2nd Orthopedic Unit of University of Florence and describe the operating technique used. They believe that the procedure of removal of nodules must always be performed in association with careful exeresis of normal tissue, employing total aponeurectomy only in revision surgery.

Adult↗
PubMed1990

[Anatomy of lower incisor root canals].

Not to know the endodontic anatomy is one of the reasons of a root canal failure. Numerous researches have demonstrated it. After a revision of the literature, the Authors expose their cases of multiple root canals in mandibular incisors. The 79 extracted teeth are studied by radiographic method in a "natural" projection and in a latero-lateral one. 29% of the examined teeth have multiple root canals. The Authors give some warning and advice to a therapeutic success in endodontic treatment of mandibular incisors.

Dental Pulp Cavity↗
PubMed1989

Regional hemodynamic effects of slow-release nicardipine in elderly patients with hypertension: evaluation by a new ultrasound technique.

Blood flow in superficial vessels was measured by means of combined two-dimensional and continuous-wave Doppler echography. In vitro validation of the technique showed precision to within 10% at flow rates greater than 300 ml/min. Assessment of common carotid artery blood flow was used to calculate vascular resistance in a single-blind, crossover study of 16 elderly patients over the age of 60 years (mean 67.7 +/- 6.5) with essential hypertension. The pulsatility index of the brachial artery was also determined. Before the study patients had previously received either placebo (twice a day) for 2 weeks or slow-release (SR) nicardipine (40 mg twice a day) for 2 months. During the study patients received a single 40 mg dose of nicardipine SR, after which mean arterial blood pressure decreased from 131 +/- 11 to 110 +/- 10 mm Hg (p less than 0.001) and from 122 +/- 13 to 108 +/- 11 mm Hg (p less than 0.001) in patients who had previously received placebo and nicardipine, respectively. Carotid vascular resistance decreased from 14.6 +/- 2.9 to 10.4 +/- 2.8 mm Hg.sec.ml-1 (p less than 0.001) and from 14.6 +/- 4.1 to 11.0 +/- 2.0 mm Hg.sec.ml-1 (p less than 0.01), respectively. The pulsatility index of the brachial artery changed from 9.4 +/- 4.4 to 9.7 +/- 8.3 and from 8.2 +/- 4.3 to 9.4 +/- 4.1, respectively (not significant). These data show that nicardipine SR reduces resistance both in the common carotid artery and in the brachial artery. Furthermore this drug appears to have an additional effect on the distensibility of the large arteries.

Aged↗
PubMed1989

Reduction of blood pressure in obese hyperinsulinaemic hypertensive patients during somatostatin infusion.

Hypertension in the obese may be related to hyperinsulinaemia. To investigate this relationship further, we infused somatostatin (250 micrograms/h in 100 ml saline) or saline, single-blind and in a random order, for 10 h in seven obese hyperinsulinaemic hypertensive patients and in seven normo-insulinaemic hypertensive controls. Every 2 h, blood pressure, plasma insulin, glucose, sodium, potassium, renin, cortisol and aldosterone concentrations and the urinary sodium:creatinine ratio were determined. Two hours after the somatostatin infusion was started, mean arterial blood pressure was significantly reduced in the obese hyperinsulinaemic patients (from 128 +/- 11 to 114 +/- 11 mmHg, P less than 0.05) but not in the controls and this reduction persisted throughout the study. The somatostatin infusion reduced plasma insulin and increased plasma glucose similarly in both groups. Plasma sodium, potassium, renin, cortisol and aldosterone concentrations and the urinary sodium:creatinine ratio were unchanged after the somatostatin infusion. These results suggest that hyperinsulinaemia could help sustain the blood pressure rise in obesity.

Adult↗
PubMed1989

[Acidogenesis and fluoride].

The Authors consider the inhibition of acidogenesis in the dental plaque by topical application of fluoride. After an examination of the actions of fluoride on the bacterial component of dental plaque, the Authors come to the conclusion that inhibition of acidogenesis is one of the possible anticaries mechanism of topical fluoride.

Adolescent↗
PubMed1988

Platelet alpha 2-adrenoceptor modifications induced by long-term treatment with indapamide in essential hypertension.

The effect of long-term treatment with indapamide in platelet alpha 2-adrenoceptors has been evaluated in 10 patients with essential hypertension, in a double-blind, cross-over study with placebo. After three months of therapy, indapamide significantly reduced mean blood pressure (from 137 +/- 12 to 116 +/- 6 mm Hg, p less than 0.001), whereas heart rate did not change (from 72 +/- 8 to 73 +/- 7 beats/minute). At the same time, platelet alpha 2-adrenoceptor number increased (from 168.2 +/- 48.4 to 256.8 +/- 14.5 fmol/mg protein, p less than 0.02), whereas the dissociation constant did not change (from 3.79 +/- 2.9 to 4.97 +/- 4.48). The plasma norepinephrine level was significantly reduced after long-term treatment with indapamide (from 275 +/- 118 to 210 +/- 56 pg/ml, p less than 0.02). These results bring about an inhibition of norepinephrine release from sympathetic nerve endings with a likely secondary increase of the number of platelet alpha 2-adrenoceptors.

Adult↗
PubMed1988

Acute effects of intravenous infusions of alcohol on baroreceptor sensitivity in essential hypertension.

To assess the acute effects of alcohol on baroreceptor reflex in moderate and heavy drinkers with essential hypertension and in healthy subjects who drank moderately, four groups of age and sex matched subjects were studied. Group 1 consisted of 10 healthy subjects (age range 21-50 (mean 37.4(10.5) years), who usually drank less than 200 g of alcohol per week; group 2 patients (age range 21-50 (mean 37.4(10.3) years) with mild or moderate essential hypertension and whose weekly alcohol consumption was less than 200 g; and groups 3 and 4 patients with mild or moderate hypertension (age range 21-50 (mean 37.2(10.2) years and 21-52 (mean 38.1(10.4) years respectively), who usually drank greater than 700 g of alcohol per week. In groups 1-3 an infusion of alcohol (7 mg.kg-1.min-1) in 500 ml of 5% glucose was administered for 1 h to keep blood concentrations constant (6-7 g.litre-1), whereas in group 4 the dose was doubled (blood concentration 10-11 g.litre-1). Baroreceptor sensitivity was measured by the phenylephrine method before and after alcohol infusion and one or two days later before and after infusion of 500 ml of 5% glucose. In healthy subjects and in moderate drinkers with hypertension the alcohol reduced baroreflex sensitivity significantly (from 17.5(9.5) to 13.8(8.4); p less than 0.01 and from 15(10) to 10.5(6.7) ms.mmHg-1, p less than 0.01 respectively), whereas in the heavy drinkers with hypertension it was significantly reduced only at the highest dose of alcohol (from 12.5(6) to 7.9(3.5) ms.mmHg-1; p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Arterial compliance and baroreceptor sensitivity after chronic treatment with indapamide.

Arterial compliance, assessed by the ratio of stroke volume to pulse pressure, and baroreceptor sensitivity (Oxford method), were determined in ten patients with essential hypertension, treated with placebo or indapamide (2.5 mg/day), in a cross-over, single blind study. After three months of therapy, mean arterial pressure was significantly reduced from 127 +/- 10 to 118 +/- 9 mmHg, (P less than 0.001), as was total peripheral vascular resistance (from 3017 +/- 561 to 2457 +/- 614 dyne/sec/cm-5/m2, P less than 0.001). Significant increases occurred in cardiac index (3.47 +/- 0.55 to 4.03 +/- 0.86 l/min/m2, P less than 0.01), baroreceptor sensitivity assessed with phenylephrine (from 11.69 +/- 7.9 to 15.0 +/- 9.1 msec/mmHg, P less than 0.01) or with nitroglycerine (from 4.77 +/- 1.6 to 7.11 +/- 2.7 msec/mmHg, P less than 0.01) and arterial compliance (from 1.27 +/- 0.42 to 1.55 +/- 0.57, P less than 0.01). A significant direct correlation was found between arterial compliance and baroreceptor sensitivity assessed during induced increase and reduction of BP, both during placebo (r = 0.88, P less than 0.001 and r = 0.77, P less than 0.01, respectively) and during active therapy (r = 0.94, P less than 0.001 and r = 0.92, P less than 0.001, respectively). These results support the conclusion that chronic treatment with indapamide enhances arterial compliances and reduces the heart load and blood vessel stress. The same effect could explain the enhancement of baroreceptor sensitivity promoted by the drug.

Adult↗