Aerosol composition and properties variation at the ground and over the column under different air masses advection in South Italy.

Aerosol composition and properties variation under the advection of different air masses were investigated, as case studies, by contemporary measurements over the atmospheric column and at the ground in a semi-rural site in South Italy. The absence of local strong sources in this area allowed to characterize background aerosol and to compare particle mixing effects under various atmospheric circulation conditions. Aerosol optical depth (AOD) and Ǻngström parameters from radiometric measurements allowed the detection and identification of polluted, dust, and volcanic atmospheric conditions. AODs were the input for a suitable model to evaluate the columnar aerosol composition, according to six main atmospheric components (water-soluble, soot, sea salt accumulation, sea salt coarse, mineral dus,t and biological). Scanning electron microscope (SEM) analysis of particulate sampled with a 13-stage impactor at the ground showed not only fingerprints typical of the different air masses but also the effects of transport and aging on atmospheric particles, suggesting processes that changed their chemical and optical properties. Background columnar aerosol was characterized by 72% of water-soluble and soot, in agreement with ground-based findings that highlighted 60% of contribution from anthropogenic carbonate particles and soot. In general, a good agreement between ground-based and columnar results was observed. Under the advection of trans-boundary air masses, water-soluble and soot were always present in columnar aerosol, whereas, in variable percentages, sea salt and mineral particles characterized both dust and volcanic conditions. At the ground, sulfates characterized the amorphous matrix produced in finer stages by the evaporation of solutions of organic and inorganic aerosols. Sulfates were also one of the key players involved in heterogeneous chemical reactions, producing complex secondary aerosol, as such clay-sulfate internally mixed particle externally mixed with soot chains.

[Age-related changes in the renin-angiotensin-aldosterone system and the sympathetic nervous system in patients with essential hypertension]. / Modificazioni del sistema renina-angiotensina-aldosterone e dell'attività simpatica nei pazienti ipertesi essenziali, con il variare dell'età.

The aim of this study was to evaluate age, plasmatic renin activity (PRA), plasma aldosterone levels and the total quantity of urinary catecholamines (TOT. UR. CAT.) in a large population of out-patients suffering from essential arterial hypertension (EAH). A total of 986 patients were examined (540 women and 426 men aged between 15 and 87 years) suffering form slight or moderate EAH (WHO stage 1-2). After a wash-out period of two weeks, systolic and diastolic arterial pressure was measured together with heart rate in clino- and orthostatism. Blood samples were collected to determine PRA and plasma aldosterone, and lastly a 24-hour urine collection was made to measure the total quantity of catecholamines. It emerged that there was a significant increase in systolic pressure, whereas heart rate and PRA diminished significantly when correlated with age; diastolic pressure was also considerably lower, but did not reach statistical significance. Moreover, it was found that there was a significant positive correlation between PRA and TOT. UR. CAT., whereas no correlation was found between age and plasma aldosterone and between blood pressure and the various endocrine parameters examined. These data confirm the changes in the biological, hemodynamic and endocrine profiles observed in elderly hypertensive patients in comparison to young hypertensive patients, and suggests that age may be an important predictive factor of the activity of both the renin-angiotensin and sympathetic nervous system which appear to be closely connected and gradually attenuated by age.

[Role of aldosterone in essential arterial hypertension complicated by chronic renal insufficiency]. / Ruolo dell'aldosterone nell'ipertensione arteriosa essenziale complicata da insufficienza renale cronica.

The following parameters were studied in a group of patients suffering from essential arterial hypertension complicated by chronic renal insufficiency (CRI), mean age = 64.31 +/- 1.84, with creatinine clearance (CrC) ranging between 30 and 60 ml/min: blood pressure (systolic and diastolic arterial pressure), heart rate, plasmatic renin activity (PRA), plasma levels of aldosterone (ALDO) both in clino- and orthostatism, as well as some metabolic parameters. All parameters were compared with those in a group of age- and sex-matched patients with slight or moderate essential arterial hypertension. Before starting the study all patients completed a wash-out period of one week to annual the effects of other drugs which might interfere with the RAA system. PRA levels were within the norm, whereas plasma levels of ALDO were high both in clino- and orthostatism. ALDO levels were also found to be inversely correlated with those of CrC. From these data it emerges that hyperaldosteronism, as observed in these patients with CRI, is a relatively reliable marker of the extent of CRI and may occur independently of the activation of the RAA system, given that other factors, such as orthostatic stimulation, alterations in the acid-base equilibrium, and the degree of aldosterone hepatic and urinary clearance, contribute to its pathogenesis.

Acute antihypertensive, diuretic and metabolic effects of etozolin and chlorthalidone.

Etozolin, a new diuretic agent, has shown a dose-dependent diuretic and saluretic effect in both experimental and clinical studies. Etoxolin, when compared to furosemide or thiazides, exerts a similar effect on urinary excretion of water and Na+, but induces a lower urinary K+ and Cl- excretion and a smaller activation of the renin-angiotensin-aldosterone system. Furthermore, the E series of the prostaglandin system seems to play a role in the mechanism of action of the drug. Seven uncomplicated hypertensive patients were included in this double blind, placebo controlled study, according to a latin square design. Each patient received three single oral doses of etozolin (200 mg, 400 mg, 600 mg), of chlorthalidone (25 mg, 50 mg, 75 mg) and one dose of placebo. Etozolin and chlorthalidone caused a similar, dose-dependent antihypertensive and diuretic effect. However, several haemodynamic and metabolic differences were observed between the two drugs. Etozolin, unlike chlorthalidone, caused no increase of heart rate, no decrease of serum K+ levels and a marked rise plasma PGE2. Moreover, etozolin caused a significantly smaller decrease of serum Na levels compared to chlorthalidone, and a significantly lower increase of supine and standing PRA, of plasma aldosterone and of the urinary excretion of Na and K. These results confirm that the acute antihypertensive and diuretic activity of etozolin occur with little involvement of the RAA system and with a significant but still unclear activation of the prostaglandin system.

Plethysmographic evaluation of the vascular effects of human calcitonin gene-related peptide in man.

Calcitonin gene-related peptide (CGRP) is a neuropeptide with potent cardiovascular effects that include positive inotropic and chronotropic actions systemic vasodilation, and hypotension in animals and in man. The mechanism of action of CGRP is still, however, not clear, and in particular it is not known whether vasodilation by CGRP occurs by changes in cutaneous or in muscular blood flow, or both. The aim of the study was, therefore, to evaluate the cutaneous and muscular blood flow, at rest and after ischemic test, induced by an IV bolus 25 micrograms human CGRP infusion in 5 healthy normotensive volunteers, using a strain gauge plethysmographic procedure with venous occlusion. Human CGRP provoked a transient but significant decrease in systolic and diastolic blood pressure, associated with tachycardia, marked flushing, a significant increase in plasma noradrenaline, adrenaline, and cyclic AMP levels, and a slight, but significant, decrease in serum total calcium. Moreover, a significant increase in the carpal cutaneous blood flow at rest was observed, with no significant change in the lower extremity muscular blood flow at rest and after ischemic test. Finally human CGRP produced a significant increase in the venous partial O2 pressure and in the hematocrit and a significant decrease in the venous partial CO2 pressure. The results of the present study confirm the acute cardiovascular and metabolic effects of CGRP. In fact, hypotension, tachycardia, flushing, and the increased cutaneous blood flow indicate a systemic vasodilation by the neuropeptide, with a secondary sympathetic response, as documented by the augmented catecholamine and cyclic AMP plasma levels.

Long-term antihypertensive treatment with lacidipine, a new long-acting calcium antagonist.

Eleven centers in Tuscany, Italy, recruited 96 patients (aged 21-75 years) with mild-to-moderate essential hypertension [diastolic blood pressure (DBP) 95-115 mm Hg; systolic blood pressure (SBP) less than or equal to 200 mm Hg]. After a 4-week, single-blind, placebo run-in period, patients received lacidipine 4 mg once daily. If blood pressure was not controlled after 1 month (control = DBP less than or equal to 90 mm Hg, or less than or equal to 95 mm Hg if reduced by greater than or equal to 15 mm Hg from baseline), the dose was increased to lacidipine 8 mg once daily. Atenolol 50 mg once daily was added after 2 months' monotherapy, if required for blood pressure control. The study continued for 13 months. About 40% of patients were titrated to 8 mg lacidipine; only 7% required addition of atenolol. Lacidipine significantly reduced blood pressure, with 84% of patients showing control of pressure values 24 h after the previous dose on completion of 5 months' monotherapy (63% controlled with lacidipine 4 mg/day; 21% with lacidipine 8 mg/day). There was no clinically relevant difference in the first-dose effect between the two doses of lacidipine (4 mg and 8 mg); both smoothly reduced blood pressure, with maximum effect after 2 h. Lacidipine was well tolerated. Adverse events were those expected with dihydropyridines, were mainly mild and occurred early, disappearing without discontinuation of treatment. Results indicate that 4-8 mg of lacidipine, administered once daily, is effective and well tolerated in mildly to moderately hypertensive patients.

[Incidence of the most frequent complications in hypertensive patients]. / Incidenza delle più comuni complicanze nel paziente iperteso.

The incidence of district (cardiac, cerebral, renal) and systemic vascular complications was studied in a population of 3992 hypertensive in-patients during the period from 1984 to 1988. The total number of male hypertensive patients was always higher (2355) than that of female hypertensive patients (1637). From the analysis of results it appears that 11.01% of male hypertensive patients and 15.85% of female hypertensive patients were diagnosed as being affected by uncomplicated essential arterial hypertension, whereas 88.97% of male and 84.12% of female hypertensive patients suffered from arterial hypertension with varying percentages of cardiac, cerebral, renal or systemic-type atheroarteriosclerotic complications. The prevalence of the male sex was particularly evident in the case of cardiac complications. Given the peak incidence of the various types of complications when analysed by decade of age, an earlier incidence of cardiac and renal complications was found in male hypertensive patients which anticipates the complications found in female hypertensive patients by approximately one decade. Lastly, the paper underlines the social importance of essential arterial hypertension and the need to develop efficacious primary and secondary prevention in order to reduce the incidence of complications which today represent the most severe aspect of hypertension.

Calcium-channel blockade (nitrendipine) in combination with ACE inhibition (captopril) in the treatment of mild to moderate hypertension.

The antihypertensive efficacy of a combination of calcium-channel blockers and angiotensin-converting-enzyme (ACE) inhibitors in severe primary hypertension is well known, but a synergistic action of this drug combination in mild to moderate primary hypertension is still not established. Therefore, the aim of the present study was to evaluate the efficacy and tolerability of monotherapy with nitrendipine (20 mg) or captopril (100 mg), and of their combination (nitrendipine 10 mg plus captopril 50 mg), in patients suffering from mild to moderate primary hypertension, according to a single-blind, randomized, placebo-controlled design. After the first 4-week monotherapy period, both nitrendipine and captopril induced a significant decrease in systolic and diastolic blood pressure (BP) (p less than 0.001). Furthermore, nitrendipine caused a significant increase in heart rate (HR), while no change in HR was observed in patients treated with captopril. Several side effects were observed, both in the nitrendipine-treated patients (facial flushing, headache, malleolar edema) and in the captopril-treated patients (initial hypotension, dizziness, gastrointestinal disorders). However, these side effects were mild and were well tolerated. In the second combined 4-week therapy period, systolic and diastolic BP of patients treated with 10 mg nitrendipine combined with 50 mg captopril continued to decrease to a degree significantly lower (p less than 0.001) than that observed at the end of the monotherapy period. Simultaneously, no change in HR values occurred when compared to basal values. Furthermore, the incidence and intensity of some side effects observed during the combined therapy period were lower than those of the monotherapy period.(ABSTRACT TRUNCATED AT 250 WORDS)

[Serum ionized calcium, parathormone and plasma renin activity in essential arterial hypertension]. / Calcio ionizzato sierico, paratormone, attività reninica plasmatica nell'ipertensione arteriosa essenziale.

Given the significance of the calcium ion in the pathogenesis of essential arterial hypertension, blood levels of total and ionised calcium, phosphorus, parathormone, blood renin activity as well as urinary calcium and phosphorus were assayed in a group of hypertensives and a comparable control group with normal blood pressure. The results showed reduced ionised calcium in the blood of the hypertensives together with hyperparathyroidism and increased calciuria. In addition, the link between parathormone and mean blood pressure levels suggests that parathormone itself play a primary role in the genesis of high blood pressure. Finally the connection between renin activity in the plasma and ionised calcium in the serum suggests that the two hormone systems are closely linked and may interact via the calcium ion.

Acute cardiovascular and renal effects of human calcitonin gene-related peptide.

Acute cardiovascular and renal effects of 25 micrograms IV human calcitonin gene-related peptide (hCGRP) have been studied in four normotensive and untreated subjects, in the absence and the presence of indomethacin, a prostaglandin synthesis-blocking agent. Intravenous infusion of hCGRP, alone, caused a transient but significant increase in heart rate (HR), hypotension, and facial flushing. Along with these effects, a positive inotropic action of hCGRP was documented by a noninvasive poligraphy. Furthermore, a significant increase in the catecholamines (norepinephrine and epinephrine), in the cyclic nucleotide (cyclic AMP and cyclic GMP) plasma levels, and a small decrease in total calcium with no change in inorganic phosphorus serum levels, occurred. Also acute renal hCGRP induced effects were observed, as a significant increase in urinary volume and in the urinary calcium, sodium, potassium, and chloride excretion. Indomethacin did not affect all the cardiovascular, metabolic, and renal hCGRP-induced effects. These results are in agreement with the hypothesis that hCGRP acts on the heart, vessels, and kidney, directly or indirectly, by the mediation of other vasodilating agents or systems excluding the prostaglandin system.

[Evaluation of the adrenergic and pressor response to the hand-grip test in young athletes]. / Valutazione della risposta adrenergica e pressoria all'"hand-grip test" nei giovani atleti.

Numerous factors may influence the sympathetic and pressure response to physical exercise, age, sex, type of activity carried on and training for example. Training, in particular is considered to reduce both adrenergic and pressure response. Plasma catecholamine levels and the haemodynamic response to the hand-grip test have therefore been evaluated in a group of young athletes, compared with a group of non-trained youths. The results confirmed that young athletes have a lower sympathetic and haemodynamic response to the isometric exercise and this is accompanied by improved cardiac performance. The value of the hand-grip test is underlined as a method of investigation able to evaluate the training level attained by the athlete.

Clinical evaluation of ceftazidime in high risk patients.

Ceftazidime was used in 19 patients at high risk owing to severe impairment of natural defense systems. The therapeutic efficacy and adverse reactions produced by cephalosporin, as evaluated on the basis of the results of clinical investigations and laboratory tests, were regarded as positive.