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Biomedical subjects

V Paoletti

Publications and source records attributed to V Paoletti.

At least 55 records · Page 3Linked to original sources

Effect of inorganic phosphate in hypoxemic chronic obstructive lung disease patients during exercise.

We have shown that normal subjects exercise more efficiently with increased plasma phosphate, presumably due to decreased hemoglobin-oxygen affinity and thus enhanced tissue O2 extraction. We subjected nine stable hypoxemic COLD patients to exercise at 0 (control), 24 (experimental) and 48 hrs (recovery) after phosphate infusion. Baseline variables were identical for each time period. Exercise responses at 0 and 48 hours were also indistinguishable. Exercise response at 24 hrs differed from those at 0 and 48 hours as follows: widening of A-V O2 content difference was more pronounced (28 +/- 6 vs 15 +/- 6 ml/L, p less than 0.03) and the increment in tissue O2 extraction was larger (14 +/- 3 vs 8 +/- 3 percent, p less than 0.03). P50 and related variables did not change during the course of the study. Thus, like normal subjects, hypoxemic patients stimulated with phosphate administration can exercise perhaps more efficiently; but, in contrast to normal subjects, this effect cannot be attributed to changes in hemoglobin-oxygen affinity. These data suggest that phosphate administration may be beneficial in hypoxemic states where adequate tissue oxygenation cannot be achieved by other more conventional methods. The mechanism of this effect remains to be elucidated.

Female↗

[Reasons for diuretic therapy of cirrhotic ascites].

The first therapeutic response to cirrhotic ascites should be a salt-free diet and bed rest. Only if this fails should anti-aldosterones, furosemide or mannitol be adopted. After an examination of the reasons for using any of these drugs, either alone or in association, it is emphasised that thiazide should never be used to treat cirrhotic ascites. Its use has been common practice for years on the basis of apparently convincing empirical evidence. Finally it is pointed out that any treatment should be approached with caution with more emphasis on the patient than on the ascites itself.

Ascites↗

A clinical trial of co-trimazine (sulfadiazine + trimethoprim) in flare-ups of chronic bronchitis.

The authors treated acute flare-ups of chronic bronchitis with a combination of sulfadiazine (SDZ) and trimethoprim (TMP) (cotrimazine). They treated thirty patients for a week, with daily dosages of 900 mg SDZ and 300 mg TMP, in an open trial in comparison with ampicillin 2 g daily. The result of treatment (course and duration of the acute episode, fever, cough, dyspnoea, sputum amount and description, chest sounds, ESR, and WBC count), tested by suitable statistical methods, showed that cotrimazine had excellent therapeutic activity and was readily tolerated; over-all results compared closely with those obtained with ampicillin. In their concluding remarks the authors state that in addition to being effective in the morbid condition selected for trial, cotrimazine offers some advantages over similar combinations of TMP and other sulfonamides, both because of the intrinsic physicochemical and pharmacological properties of SDZ and because of its lower dosage in this combination.

Acute Disease↗

Clinical trial of xipamide in the treatment of hypertension.

Nine patients with hypertension were given xipamide 40 mg orally as monotherapy on alternate days. An additional seventeen patients had xipamide added to an existing treatment regime of clonidine 450 micrograms per day. Xipamide alone produced a significant fall in blood pressure comparable to that obtained with clonidine alone. However, a significant further reduction was obtained when xipamide was added to the existing clonidine regime.

Administration, Oral↗

Morphologic left ventricular patterns and prevalence of high-grade ventricular arrhythmias in the normotensive and hypertensive elderly.

In the elderly, systemic hypertension is the main risk factor for cardiovascular diseases. Left ventricular hypertrophy, the most common adaptation to chronic pressure overload, has been recognized as an independent risk factor for an increased incidence of sudden death and arrhythmic disturbances. This study compared the prevalence of serious ventricular arrhythmias in elderly individuals with uncomplicated hypertension and in normotensive age-matched controls, using left ventricular mass index (LVMI) to differentiate patterns of anatomic adaptation to systolic, diastolic, or systolic-diastolic hypertension. The study enrolled 378 consecutive untreated elderly subjects (> or = 65 years of age), without clinical evidence of heart failure; 203 were hypertensive and 175 were normotensive. Each participant underwent standard 12-lead electrocardiography, M-mode and B-mode echocardiography, and 24-hour ambulatory electrocardiographic monitoring. Serious, statistically significant arrhythmias (Lown classes > or = 3) were present in 6.8% of normal subjects versus 17.1% of individuals with systolic, 31.5% of those with diastolic, and 20.4% of participants with systolic-diastolic hypertension. Arrhythmias did not differ in terms of left ventricular morphologic patterns or LVMI or between subgroups of hypertensive patients. Our data support the hypothesis that the pathogenesis of arrhythmias is related not to the electrophysiologic derangement of hypertrophied muscle but, rather, to the effects of hypertension on the cardiac structure. Cardiac fibrosis, one of the deleterious events accompanying hypertension, may be the main substrate for ventricular arrhythmias.

Aged↗

Natural history of cardiac involvement in myotonic dystrophy (Steinert's disease): a 13-year follow-up study.

Myotonic dystrophy (MD) is associated with a wide spectrum of cardiac abnormalities, but only a few longitudinal studies have investigated the natural course of heart disease in MD. To assess whether neuromuscular involvement significantly predicts cardiac disorders in MD, 83 patients with various grades of disease severity were enrolled in a 13-year follow-up study (mean, 60.6 +/- 37.8 months) that included periodic physical and instrumental cardiac examinations (standard and Holter electrocardiography, echocardiography). During follow-up, muscular disease worsened clinically in 9 patients (11%) whose baseline severity grade changed accordingly; only 3 of them demonstrated parallel worsening of cardiac disturbance, however, compared with a large number of patients who showed additional cardiac abnormalities. These included further worsening of pre-existing pathologic features (19/83) and the appearance de novo of serious arrhythmias and/or conduction defects (23/83). Pacemaker implantation was necessary in 11 of 83 patients (13.2%) who had symptomatic bradyarrhythmias, bifascicular block, and P-R prolongation with a His-to-ventricle interval exceeding 55 ms, as documented by electrophysiologic study. Eight (9.6%) patients died: 2 from noncardiac and 1 from unknown causes, 1 from heart failure, and 4 from sudden death closely related to documented ventricular tachycardia. The incidence and seriousness of arrhythmic and conduction disturbances correlated with the severity of the muscular involvement. Nevertheless, cardiac and muscular disease did not show a linear progression. Cardiac involvement generally worsened more rapidly than did skeletal muscle disease.

Adolescent↗

Adrenomedullin assay and its clinical significance.

Adrenomedullin (Am) is a recently discovered peptide, first purified from pheochromocytoma specimens, with a chemical structure similar to that of CGRP and amylin. Adrenomedullin is present in numerous human body tissues and its powerful vasodilatatory activity is thought to play an essential role in cardiovascular and renal homeostasis.

Adrenomedullin↗

CGRP and ET-1 plasma levels in normal subjects.

OBJECTIVE: Calcitonin gene-related peptide (CGRP) is a 37 amino acid peptide displaying about 50% homology with amylin which is secreted from the pancreatic islets of Langerhans. The main form, the beta-CGRP, is produced by the enteric nervous system and perivascular nerves of the vasa-vasorum. It represents one of the most powerful vasodilator yet discovered but its role is not yet completely clarified. High levels of this peptide have been shown in patients affected with thyroid medullary carcinoma, phaemocromocytoma and lung carcinoma. Recently circulating levels of CGRP have been found in normal subjects. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, isolated from porcine endothelial cells, is an important regulator of the vascular tone acting in physiological antagonism with atrial natriuretic hormone (ANH). With this study we intended to investigate the presence of any correlation between CGRP and ET-1 in normal subjects. PATIENTS: For the study we considered 20 normal subjects (11 males and 9 females) aged 23 to 50. MEASURES: Plasma levels of CGRP and ET-1 were measured by radioimmunological Kit. RESULTS: A positive and significant correlation between calcitonin gene-related peptide and endothelin-1 was found. CONCLUSIONS: Our results confirms that CGRP and ET-1 have opposing actions on vessels and that they can act together in haemodinamic regulation.

Adult↗

[Rationale for the use of renin-angiotensin inhibitors in the treatment of arterial hypertension and correlated organ damage].

The treatment of hypertension has evolved in recent years. Blood pressure lowering per se is no longer a sufficient parameter to evaluate its beneficial effects on end-organ damage. Drugs must be considered on the basis of their effects on cellular level and structural alterations that occur in the vasculature, heart and kidney. Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, two classes of drugs that inhibit angiotensin II effects, may protect target organs from damage and thereby improve outcomes. The mechanisms of action are different even if both counteract all noxious effects of angiotensin II. Angiotensin II receptor blockers selectively inhibit AT1 receptors whose stimulation mediates the hypertensive and proliferative effects of angiotensin II while do not interfere with AT2 receptors. These last ones have a role not well established but it has been postulated that they have antihypertensive and antiproliferative effects. A review will be made on the cellular mechanisms of angiotensin II activity and the effects of AT receptor antagonists.

Angiotensin-Converting Enzyme Inhibitors↗

[Efficacy-safety relationship of AT1 angiotensin II receptor antagonists: current data].

In evolution of hypertension's treatment it may no be sufficient to lower blood pressure to achieve beneficial effects in long term outcomes. Several goals of antihypertensive treatment remain unrealized. There is so great interest for new drugs that may protect target organs and improve outcomes. The angiotensin II, the major effector of the renin-angiotensin-aldosterone system, causes a variety of potentially noxious cardiovascular effects which are specially mediated by AT1 subtype receptors. AT1 receptor blockers (losartan, candesartan, irbesartan, valsartan) are available drugs in the angiotensin-II-antagonist class. This paper examine the peculiar features of this new class of drugs.

Angiotensin Receptor Antagonists↗