Immunopathology of liver allografts and xenografts in nonhuman primates.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E Arosio.
Explore the source record for details and available documents.
Intracellular platelet pH was studied by the BCECF fluorescent pH-sensitive intracellular indicator method in 52 patients with essential hypertension and 42 control subjects of similar age and sex. In 40 hypertensive patients studied by oral glucose tolerance test (standard OGTT) 23 presented with pathological blood glucose and plasma insulin values. Intracellular pH was on average higher in hypertensives (7.415 +/- 0.114, mean +/- SD) than in controls (7.348 +/- 0.109, P < 0.05), although there was a considerable overlap in values. In the group of hypertensive patients, no difference was observed between those with normal and those with pathological OGTT. There was also no significant correlation between intracellular pH and blood glucose, plasma insulin after OGTT, plasma cholesterol and triglycerides, age, BP or body mass index. These data are consistent with an anomaly of intraplatelet pH, perhaps owing to alteration of Na+/H+ exchange in essential hypertension, but do not indicate that this is related to a condition of hyper-insulinaemia or insulin resistance.
Little is known about the distribution of IgG-bearing cell subpopulations in normal liver and their possible changes in disease conditions. We developed an immunohistochemical method that proved suitable and accurate for the identification and characterization of IgG-bearing cells and their subpopulations in liver specimens. The method uses specific monoclonal antibodies on serial mirror liver sections. We applied this method to four normal liver tissue specimens and 25 liver biopsy samples of chronic hepatitis of viral etiology. Only rare IgG-bearing cells could be observed in the portal tracts of normal liver specimens. In contrast, a dense infiltrate of such cells was seen in liver specimens from patients with chronic viral hepatitis. The density of IgG-bearing cells in such patients ranged from 6 to 20 cells x 10(-4) micron2 in the different specimens (mean = 11 x 10(-4) micron2). The increase in IgG-bearing cells did not appear to be related to the histological diagnosis, to the degree of histological inflammatory activity or to the type of viral infection. The major population of IgG-bearing cells consisted of IgG1-positive cells (68%); IgG2- (17%), IgG3- (8%) and IgG4 (7%)-bearing cells represented only minor fractions. The increased prevalence of IgG1-bearing cells observed in chronic hepatitis but not in normal liver specimens suggests that these findings may reflect an activation of antibody production directed toward viral antigens or antigenic structures of self. The identification of the antigenic specificities of the antibodies produced by IgG-bearing cells might provide important clues in understanding the pathogenesis of chronic viral hepatitis.
Haemodynamic changes in the carotid and brachial arteries produced by single doses of four anti-hypertensive drugs (nicardipine, enalapril, atenolol, and urapidil) have been studied in 12 patients with essential hypertension. Measurements were performed noninvasively using a mechanographic method and B-mode pulsed Doppler ultrasonography. Within 7 h all of the drugs had caused a significant reduction in blood pressure, whereas heart rate showed a significant change only after atenolol. All the drugs produced a marked reduction in brachial pulse-wave velocity. Only nicardipine caused a significant reduction in vessel wall tension both in the carotid and brachial arteries, while brachial peripheral resistance was significantly reduced by all the drugs except atenolol. Neither atenolol nor enalapril caused any significant reduction in carotid peripheral resistance. The results show that all four antihypertensive drugs led to a beneficial increase in arterial compliance despite their different effects on peripheral resistance.
Explore the source record for details and available documents.
Effects of picotamide (900 mg in 3 oral administrations for 7 days) on ex vivo and in vivo platelet TxA2 production and on platelet aggregation were evaluated in 8 patients with peripheral arteriopathy and in 8 normal subjects. Picotamide significantly reduced ADP-induced platelet aggregation, but had no effect on that induced by arachidonic acid or the thromboxane analogue U46619. Though ex vivo platelet TxA2 production (TxB2 concentration after arachidonic-acid-induced aggregation) was reduced from 946 +/- 141 (mean +/- SD) to 285 +/- 91 ng/ml in controls and from 1515 +/- 673 to 732 +/- 420 ng/ml in patients with arteriopathy, there was no effect on urinary excretion of 2,3-dinor-TXB2 (in vivo indicator of platelet TxA2 production), or on in vivo PGI2 production (urinary excretion of 6-keto-PGF1 alpha and 2,3-dinor-6-keto-PGF1 alpha). In the same subjects, single-dose aspirin reduced ex vivo TxB2 production by at least 98% and 2,3-dinor-TxB2 excretion from 116.7 +/- 61.4 to 32.6 +/- 17.0 ng/g creatinine in control subjects, and from 156.3 +/- 66.1 to 59.1 +/- 19.2 ng/g creatinine in patients with peripheral arteriopathy. Our data suggest that inhibition of platelet TxA2 production in vivo may not be picotamide's main mechanism of action.
After a two-week washout (WO) period with placebo 1 capsule/bid, 12 patients suffering from stable Raynaud's phenomenon were treated with ketanserin (K) 40 mg/bid for fifteen days. Blood pressure, heart rate, and laboratory parameters were evaluated at the end of each period. Patients used diary cards to record the number, duration, and intensity of attacks. Computerized thermometry of the fingers was evaluated at basal temperature after acclimatization, 23 degrees C for thirty minutes; after cold test, 10 degrees C for five minutes; and after thermal recovery, 23 degrees C for eighteen minutes. Results were analyzed statistically by use of Student's t-test for paired data (p less than 0.05). No marked changes were observed in the symptoms of the attacks, but K proved effective in significantly reducing the number and duration of daily attacks and in promoting their spontaneous regression. Thermometry revealed a parallel increase in temperatures, particularly basal and recovery values. The data suggest increased flow and decreased vasospasm following 5-HT2 receptor blockade.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effects of nifedipine SR and lacidipine on blood pressure, left ventricular (LV) hypertrophy, and diastolic function were evaluated in 15 male patients (mean age of 45 +/- 8 years) with mild-to-moderate hypertension. Clinical evaluation and complete echocardiography were performed at baseline (after 15 days of washout). Seven patients received nifedipine SR (20-40 mg twice daily) and eight lacidipine (4-6 mg once daily). Clinical evaluation and complete echocardiography studies were repeated after 1 and 6 months of active treatment. In addition, full echocardiographic evaluations were carried out in 10 normotensive subjects (for comparison). Results were similar with either drug. After 1 month of therapy, systolic and diastolic blood pressures were significantly decreased (p less than 0.05); after 6 months of therapy, further changes were observed, confirming their significance. Analysis of our data suggests that (a) mild essential hypertension induces early modifications of LV geometry with consequent LV diastolic function characterized by a prolonged and incomplete diastolic filling; thus, LV wall thickness may be increased with a simultaneous reduction in LV end-diastolic short-axis diameter and volume; and (b) antihypertensive treatment with calcium antagonists such as nifedipine SR and lacidipine leads to early normalization of LV geometry and diastolic function without a significant change in total LV mass.
The effects of nifedipine on blood pressure (BP), left ventricular hypertrophy, and diastolic function were evaluated in 14 patients with essential hypertension (EH). All males with a mean age of 44 +/- 6 years (range 35-58 years), and in ten normotensive subjects (control group) aged 32-42 years (mean age 36 +/- 4). A complete echocardiogram (ECHO) was performed in basal conditions after 1 and 6 months of therapy with nifedipine (20-40 mg/day). Left ventricular echocardiograms (LV ECHO, M-mode, two-dimensional guided) were plotted with a simultaneous ECG tracing by means of a computerized system that allows evaluation of the following parameters: LV end-diastolic and systolic diameters (EDD, ESD); variations in LV diameter and volume during the entire cardiac cycle, and the velocities of such variations; end-diastolic thicknesses of the interventricular septum and posterior wall (ST, PWT); LV mass, mass/volume (M/V) index, end-diastolic diameter/thickness (D/Th) index, and LV ejection fraction (EF). Left ventricular volume curves were obtained and the contributions of rapid filling (RF) and atrial systole (AS) to EDV were evaluated. Filling velocities during RF (vRF) and AS (vAS) were estimated, as well as the isovolumic relaxation period (IR). No significant changes were observed in the heart rate. After 1 month of therapy, systolic and diastolic BP were significantly decreased (p less than 0.05). ST and PWT were reduced, with a simultaneous increase in EDD and EDV (p less than 0.01). LV mass was slightly reduced, as was the M/V index. The D/Th index was increased (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Eighty-seven laser angioplasty procedures were performed on 85 patients (73 men and 12 women). In the first phase (54 patients) a broad selection process included long occlusions (23.9 cm avg) and vessels with heavy calcification; in the second phase (31 patients) the authors treated vessels with shorter occlusions (10 cm avg) and less calcific. The primary success rate, based on number of procedures (73.5% overall) was 69% in the first phase but reached 81.3% in the second phase. There were 14 perforations (16%), 8 dissections (9.4%), and 4 peripheral emboli (4.7%). Six-month follow-up shows that the Winsor index maintained its initial improvement in 76.5% of all patients, or 62% in just the long occlusions. These data and a review of the cases suggest that no more of 10-20% of patients with claudication in lower extremities can be treated by laser angioplasty; the authors consider ideal candidates those patients who noncalcific lesions in the common iliac or superficial femoral arteries at the III medium level with obstructions shorter than 8 cm and good runoff.
The effects of the calcium-entry blocker nicardipine on brachial hemodynamics were studied in 22 patients (18 male, 4 female) with essential hypertension, who were treated with 20 mg tid for 1 year. Compliance, characteristic impedance, vascular resistances, and tangential tension were measured before treatment and after 1, 3, and 12 months of treatment by an automatic recording from a B-mode, high-resolution, real-time scanner and pulsed Doppler velocimetry for the calculation of the flow volume. We observed statistically significant variations in compliance and impedance after 1 month (3.21 +/- 0.59 dyn-1 cm4 10(-7) vs. 1.26 +/- 0.16 dyn-1 cm4 10(-7) and 50.6 +/- 4.7 dyn s cm-510(2) vs. 91.4 +/- 7.3 dyn s cm-5 10(2), respectively; mean +/- SEM; p less than 0.001), while tangential tension was significantly reduced after only 3 months (23.2 +/- 2.2 mmHg vs. 25.4 +/- 2.3 mmHg cm; p less than 0.05). The correlation between variations in mean blood pressure and in the hemodynamic parameters studied remained statistically significant throughout the study. Nicardipine improved the parameters of large-artery hemodynamics that favor a normal systolic pulse.
Increased platelet aggregation induced by ADP and arachidonic acid was observed in 12 patients with essential hypertension compared with 12 control subjects, but not after pretreatment with acetylsalicylic acid. The increase in intracellular calcium induced by ADP was also greater in the hypertensive patients, and again this difference disappeared after cyclo-oxygenase blockade. Urinary excretion of 2,3-dinor-thromboxane B2, the main metabolite of platelet thromboxane A2, was slightly, but not significantly increased in the hypertensive patients. These data suggest that thromboxane system activity is increased in the platelets of hypertensive patients.
We conducted a randomly allocated, double-blind study in 16 essential hypertensive patients, eight of whom were treated with nifedipine and eight with lacidipine. The antihypertensive efficacy was evaluated and any modifications to peripheral haemodynamic parameters were observed in the brachial artery by a mechanographic method and B-mode scanner with a 10-MHz probe. Statistically significant reductions in blood pressure from basal values were observed after 1 and 6 months' treatment. Enhanced compliance (P less than 0.005), reduced characteristic impedance (P less than 0.001) and lower peripheral resistances (P less than 0.01) were also noted. Variations in pulse wave velocity and mean blood pressure showed a statistically significant correlation as early as the first month of treatment (P less than 0.01). Our results suggest that therapy with nifedipine and lacidipine allows an improvement in peripheral haemodynamics in hypertensive patients. This response is maintained in chronic treatment, even just before the next dose administration at the end of the longest dose interval.
In a randomized, placebo-controlled, crossover study, 15 ambulatory patients with Raynaud's phenomenon, treated for three weeks with ketanserin 80 mg/day and pentoxiphylline 1,200 mg/day, were evaluated by subjective symptom scores, daily frequency and duration of attacks, and photoplethysmography, at room temperature and after cold test. Reduced subjective symptoms and duration of attacks, together with improved cold test plethysmography, were significant only after ketanserin. All subjective symptom scores also improved after ketanserin but only for cyanosis and paresthesia after pentoxiphylline. Excellent results were obtained in 4 cases after ketanserin and in 1 case with pentoxiphylline. The authors discuss the greater importance of antivasospastic action over antiaggregating and hemorheologic effects in Raynaud's phenomenon therapy, as well as the pathogenetic role of serotonin.
The Authors analyze the clinical and biological meanings of some markers of coagulative activity (beta thromboglobulin, PF4, fibrinogen, fibrinopeptide A) and their changes in some arterial diseases. The role of main atherosclerosis risk factors (dyslipidaemia, hypertension, smoking and diabetes) in promoting a thrombophylic state in these pathological conditions is also considered. Finally the Authors evaluate the usefulness of the markers of coagulative activity from both a diagnostic and a preventive point of view in the arteriopathies of atherosclerotic etiology.
In a pilot study, defibrotide was administered to 22 patients with arterial occlusive disease of the lower limbs (mean age 59 years; range 48-71 years), of whom 12 were Fontaine 2nd stage and 10 Fontaine 3rd stage. In the first group, treatment enabled significant improvement in the walking distance (580 +/- 95 vs 220 +/- 65 m; M +/- SD; p less than 0.001), even 15 days after discontinuation of therapy (445 +/- 110 m; p less than 0.05). In 3rd stage patients, treatment caused reasonable reduction of pain, with elimination of resting pain in 4 patients. Both groups underwent no modification of Doppler velocimetry and Winsor index, while photoplethysmography in 8 patients at 2nd- and in 3 patients at 3rd-stage showed improvement at the end of treatment. There were no modifications of hepatic, renal, hemopoietic and hemocoagulative functions. Beta-thromboglobulin showed a statistically significant reduction (62 +/- 10 vs 116 +/- 18 ng/ml; M +/- SEM; p less than 0.001), from 2 weeks after the first dose until 15 days after discontinuation of therapy. Defibrotide proved particularly efficacious in Fontaine 2nd-stage patients, showing its suitability for treating the stages of occlusive atherosclerotic disease at which collateral circulation can still be activated.