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Biomedical subjects

F Fontana

Publications and source records attributed to F Fontana.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Changes in plasma myoglobin levels in ischemic heart disease].

The aim of the present study is to evaluate the real need and the sensitivity of serum myoglobin levels as an early index for the diagnosis of acute myocardial infarction. A total of 62 patients (38 suffering from acute myocardial infarction, 16 from "angina pectoris", 8 from heart failure) and 20 healthy volunteers were included in the study. The patients with acute myocardial infarction were divided in 3 subgroups according to the time passed between the beginning of the pain and their admittance to our Department (Coronary Care Unit), that was, less than 6 hours, between 6 and 12 hours, between 12 and 24 hours. Among the patients with "angina", 8 presented spontaneous crisis whereas 4 had crisis only during treadmill test. 8 of the healthy volunteers received intramuscular injections of physiological solution every 12 hours during the 3 days preceding the study. In all subjects serum myoglobin level were measured by radioimmunoassay; in patients with acute myocardial infarction serum CK and MBCK levels with enzymatic method were measured too. No variation of plasma myoglobin levels was seen in patients with angina, neither in healthy volunteers had they received or not intramuscular injections. The low increase in plasma myoglobin levels observed in patients with heart failure might be due to a deficit of renal function. Serum myoglobin levels were significantly elevated in all the patients with acute myocardial infarction, whereas plasma CK and MBCK levels were significantly high only 6 hours after the necrosis. In myocardial infarction the levels of myoglobin rise during the first hours, peak at 10 hours and return to normal in 20 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1989

Changes in prostaglandin renal synthesis in cardiovascular disease.

We investigated the factors able to stimulate (hormones, drugs, fluid volume changes and prostaglandin precursors) or inhibit (NSAIDs) renal prostaglandin synthesis. We then assessed the effects of NSAIDs on: A) the efficacy of certain drugs (furosemide, ACE-inhibitors), whose action is mediated by a stimulation of prostaglandin synthesis; B) the physiopathology of cardiovascular diseases such as myocardial infarction and heart failure, in which renal and circulatory output is reduced; C) arterial hypertension.

Cardiovascular Diseases↗
PubMed1988

[Hemodynamic and renal effects of synthetic atrial natriuretic factor (alpha-h-ANF) in patients with congestive heart failure].

We studied the effects of alpha-human atrial natriuretic factor (alpha-h-ANF) on diuresis, glomerular filtration rate (GFR), natriuresis, atrial blood pressure (BP), heart rate (HR) and plasmatic levels of aldosterone, renin activity (PRA), antidiuretic hormone (ADH) in 21 patients with congestive heart failure (CHF), (NYHA, class IV) and 15 healthy volunteers. Three different doses (25, 50 and 100 micrograms) of alpha-h-ANF were administered; each subject received only one dose. Protocol was as follows: 2 periods of 30 minutes each before alpha-h-ANF administration; 2 periods of 15 minutes and 3 of 30 minutes each after it. Aldosterone, PRA, ADH and plasmatic level of ANF were measured by radioimmunoassay. In patients with CHF 25 and 50 micrograms of alpha-h-ANF produced a significant increase in diuresis, GFR, and natriuresis but no modification of BP. On the contrary BP decreased significantly after 100 micrograms of alpha-h-ANF, without changes in renal function. In healthy volunteers the effects of alpha-h-ANF appeared simultaneously and to same degree after each dose. Both in patients and healthy subjects alpha-h-ANF administration had little effect on aldosterone, renin and ADH secretion. The effects of alpha-h-ANF in patients with CHF may be caused by a lowered receptor sensitivity due to a high level of ANF and to their different haemodynamic status.

Aged↗
PubMed1987

Cytogenetic studies on Cervus elaphus. II. Synaptonemal complexes and NOR activity during spermatogenesis.

The activity of the nucleolus organizer regions (NORs) in various stages of spermatogenesis of the red deer was studied with the silver staining technique. The Ag-stainability of the NORs, an indicator of the transcriptional activity of the r-RNA genes, is present during the meiotic prophase until pachytene and is absent during the remainder of the meiotic prophase, to reappear during the first stages of spermiogenesis and then disappear again during the elongation phase of the spermatids. The development and behaviour of synaptonemal complexes (SCs) of primary spermatocytes were also studied with the silver staining technique under the light microscope. The organization of SC is similar to that of other mammalian species. The pairing behaviour of the axes of the sex chromosomes is described.

Animals↗
PubMed1987

Clinical trial with muzolimine in healthy and hypertensive subjects: new vistas on the drug action.

The mechanism of muzolimine (3-amino-1-[3,4-dichloro-alpha-methyl-benzyl]-2 pyrazolin-5-one) action is still not completely defined. The identified site of action is the Henle loop, similarly to furosemide which acts also by mediating renal prostaglandin synthesis. The aim of the present study was to evaluate the early effects of muzolimine (30 mg per os) on renal function and prostaglandin urinary excretion in healthy controls and hypertensive subjects. Urinary flow reached the peak values by the third hour after the drug and a diuretic effect not directly dependent on glomerular filtration was observed, especially in hypertensive patients. In these cases the diuresis increased also due to a low glomerular filtration rate and tubular phenomena were more evident than in controls: an increasing Na+ tubular excretion and a parallel decreasing % Na+ reabsorption. Blood pressure was not significantly influenced by muzolimine in healthy subjects, while it returned to normal values in the hypertensive group. A cyclooxigenase inhibitor, lysine acetylsalicylate (1 g i.m.) administered 10 minutes after muzolimine, was not able to modify the parameters under consideration. Therefore a mediation by prostaglandins on the diuretic and antihypertensive effects of the drug under study may probably be excluded.

Aged↗
PubMed1986

Effects of polyunsaturated fatty acids and prostaglandin synthesis on renal function.

The effects of polyunsaturated fatty acids (phosphatidylcholine) on renal function in healthy subjects and in patients with chronic renal failure, with liver cirrhosis, and with heart failure were studied. The drug was administered at 3.5 mg/kg i.v. (Linoleic acid 1.24 mg/kg). In all cases, the administration of the drug caused an increased excretion of sodium and especially of water with a reduction in basal urinary hypertonicity. The polyuria was caused by the higher glomerular filtration rate not being counterbalanced by an increase in tubular water reabsorption. The water reabsorption was mostly anisosmotic. The presence of urinary hypertonicity excluded an inhibition of ADH secretion by this drug. The sodium excretion was probably caused by an increase of the glomerular filtration rate whereas no significant changes in the tubular reabsorption of sodium were seen. We found a significant (p 0.05) increase in PGE2 urinary excretion after phosphatidylcholine administration. Lysine - acetylsalicylate injection after phosphatidylcholine, in other trials in the same patients, prevented the effects previously reported. Therefore we suggest that the effects of this drug are mediated by an increased availability of renal prostaglandins.

Aspirin↗
PubMed1982

Hemodynamic and metabolic effects of nitroglycerin ointment in pacing-induced angina pectoris.

Hemodynamic and metabolic effects of nitroglycerin ointment (40 mg nitroglycerin) were tested on 15 patients with clinical evidence of stable angina. Basal value (B) and atrial pacing (AP)-dependent changes were evaluated before and 30 min after ointment administration. After treatment tension time index (TTI) basal value showed a 19% reduction (p less than 0.05). Compared to the control a lesser AP-dependent increase was also noted (27%, compared to 45%; p less than 0.005). According to TTI reduction, MVO2 showed an evident decrease both in basal conditions and during AP (21% and 29.6%, respectively). On the contrary, diastolic pressure time index (DPTI) does not result significantly influenced by the treatment. Consequently, DPTI/TTI ratio increase is largely the result of TTI reduction, which is well correlated to myocardial oxygen demand. Coronary sinus blood flow decrease (16% and 27% under basal conditions and during AP, respectively) confirms that the therapeutic efficacy of the ointment does not result from an increase in myocardial oxygen supply. Finally, during AP nitroglycerin ointment resulted in a significant decrease in myocardial lactate release (L% mean value ranges from-17.5% to 3.4%; p less than 0.001). Such an improvement probably reflects a primary influence of the drug on the extracoronary vascular bed.

Adult↗