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Biomedical subjects

L Campanacci

Publications and source records attributed to L Campanacci.

At least 37 records · Page 2Linked to original sources

Primary bone tumors of the spine: a survey of the evaluation and treatment at the Istituto Ortopedico Rizzoli.

The experience at Istituto Rizzoli with 366 primary bone tumors of the spine focuses on the criteria for planning and treatment. An accurate preoperative evaluation by standard radiograph, computerized tomography scan, and magnetic resonance imaging allow the classification of benign lesions as latent (not requiring treatment), active (curettage), or aggressive (curettage plus adjuvants or marginal resection). The malignant lesions are classified as intracompartmental or extracompartmental (both low and high grade). Wide resection is attempted, but seldom is feasible. An angiographic study of the spinal cord is compulsory for lesions located in the thoracolumbar region. The value of embolization is enhanced, primarily in highly vascular lesions. An accurate preoperative study of the vital parameters of the patient, together with a continuous intraoperative monitoring, is mandatory.

Adult↗

Cytokeratin expression and distribution in adamantinoma of the long bones and osteofibrous dysplasia of tibia and fibula. An immunohistochemical study correlated to histogenesis.

Twenty-four cases of adamantinoma and 24 cases of osteofibrous dysplasia of the long bones were studied to evaluate the expression and distribution of cytokeratin (CK) subtypes in relation to histogenesis and differentiation. The immunohistochemical study was performed on tissue fixed in buffered formalin and embedded in paraffin wax utilizing antibodies to vimentin, factor VIII, epithelial membrane antigen and cytokeratins of different molecular weights. In all cases the vimentin antibody marked positively in stroma, endothelium and osteoblasts, while factor VIII expression was confined to endothelial cells. In 71% of adamantinomas, vimentin showed strong immunoreactivity in the tumour cells of nests and tubules. CKAE1/AE3 and CK19 were strongly expressed in all morphological patterns of adamantinoma emphasizing their epithelial origin, while the antibodies to CK8 and CK18 showed a high percentage of negative responses. In osteofibrous dysplasia the epithelial-like component was much smaller than in adamantinoma and was present in scattered islands composed of a few cell positive for CKAE1/AE3 and CK19 and negative for other keratins. These results suggest that these two lesions are of a similar histogenesis.

Ameloblastoma↗

Ace inhibition in renal disease: risks and benefits.

The kidney is one of the principal target organs of hypertension and most diseases of the kidney are associated with blood pressure elevation. Studies in animal models of hypertensive renal disease have provided insights into the complex relationship between systemic and glomerular hypertension. The intrarenal renin-angiotensin system (RAS) appears to play an important role in the pathogenesis of progressive glomerular injury. Thus, angiotensin converting enzyme inhibitors (ACEi) may have a specific therapeutic advantage in the treatment of hypertension associated with progressive renal disease. However, in contrast to their possible renoprotective effect in diabetic nephropathy or in renal hypertension, there are increasing evidence that, in the presence of a reduction in renal perfusion, intrarenal haemodynamic effect of ACEi may lead to compromised renal function. ACEi appear to have dual effects on renal function depending on the setting in which they are administered.

Angiotensin-Converting Enzyme Inhibitors↗

Peripheral adrenoceptors in hypotension of hemodialyzed uremic patients.

Hypotension is a common problem in patients on hemodialysis. To further investigate this problem, the number of platelet alpha 2-adrenoceptors and the activity of lymphomonocyte beta 2-adrenoceptors were measured in 10 hemodialyzed patients with normal blood pressure and in 10 sex- and age-matched persistently hypotensive hemodialyzed patients. Density of alpha 2-adrenoceptors was assessed by the specific binding of 3H-yohimbine to intact platelets, while the function of beta 2-adrenoceptors was estimated by the production of cAMP after the exposure of lymphomonocytes to isoprenaline. The maximal number of alpha 2-adrenoceptors was increased in the hypotensive compared to the normotensive group (262.13 vs. 77.21 fmol/mg protein; p < 0.01). Plasma norepinephrine was higher in the hypotensive than in the normotensive uremic patients (640 +/- 195 vs. 344 +/- 156 pg/ml; p < 0.01). Plasma epinephrine did not differ in the two groups (90 +/- 30 vs. 94 +/- 24 pg/ml). The amount of cAMP, produced by stimulation of lymphomonocytes, was lower in the hypotensive than that in the normotensive uremic patients (7.7 +/- 2.4 vs. 15.6 +/- 5.4 pmol/10(6) cells; p < 0.002). The increased number of alpha 2-adrenoceptors together with a high level of norepinephrine and reduced activity of adenylate cyclase (coupled with beta 2-adrenoceptors) support the hypothesis that hypotension in the hemodialyzed uremic patients may be related to a defect in adrenoceptor coupling mechanisms.

Adult↗

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↗

[Arterial hypertension and the kidney in pregnancy].

Hypertension complicates approximately 10 per cent of all pregnancies and accounts for 20% of all maternal deaths. Blood pressure normally decreases in the first trimester of pregnancy, secondary to a decrease in peripheral vascular resistance, reaches its lowest point in the second trimester and then gradually increases to or near pregravid levels at term. Normal pregnant women develop vascular resistance to the pressor effect of angiotensin II, which is precociously lost in women who develop gestational hypertension. Prostaglandins seem to be involved in the development of this vascular refractoriness. An acute and reversible lesion--defined "Glomerular endotheliosis"--has been described as the basic pathologic pattern of pre-eclamptic nephropathy, although gestational hypertension can be superimposed on undiagnosed essential hypertension or any of a variety of renal diseases. The primary goal when treating gestational hypertension is successful termination of the pregnancy with the least trauma to mother and fetus. Antihypertensive drugs could be administered to prolong pregnancy when this is considered desirable, although pharmacological therapy of gestational hypertension remains a subject for dispute, because of the lack of closely controlled studies. Hydralazine and methyldopa are drugs with a long history of use in gestational hypertension. Beta-blockers have been shown to be as effective as methyldopa. Clinical experience with nifedipine is limited, but controlled clinical trials, currently in progress, suggest its suitability.

Adolescent↗

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↗

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↗

ACE inhibitors: antihypertensive treatment and renal function.

Much clinical evidence supports the use of angiotensin-converting enzyme inhibitors (ACE-I) as the first-step drugs in the treatment of essential hypertension. The acute and chronic effects of ACE-I on renal function are reviewed in this paper. The kidney is an important target organ of essential hypertension and some antihypertensive drugs have been shown to decrease renal haemodynamic parameters. In hypertensives with normal renal function, ACE-I were demonstrated to be safe drugs: after acute and chronic administration of these drugs, the drop in blood pressure was accompanied by unchanged or increased GFR and RPF, with decreased renal vascular resistance. Only in patients with renovascular hypertension, with bilateral stenosis or solitary kidney, was there a deterioration in renal function.

Angiotensin-Converting Enzyme Inhibitors↗

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↗

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↗