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Biomedical subjects

M G Matera

Publications and source records attributed to M G Matera.

At least 91 records · Page 5Linked to original sources
PubMed1990

Cardiac function and sympathetic activity in young diabetics.

This study was aimed at evaluating cardiac function, both systolic and diastolic, in young type 1 diabetics with a mean duration of the disease of 10.9 +/- 6 years and without evidence of cardiac autonomic neuropathy and micro- or macroangiopathy. Thirteen diabetics, with good metabolic control, and 10 normal matched subjects were studied by echocardiography at rest and by radionuclide ventriculography both at rest and during effort. The level of plasma catecholamines was also determined. The echocardiographic data were comparable in the two groups. Scintigraphic data showed an increased peak ejection and peak filling rate (P less than 0.001) in diabetics while the other indices of cardiac function were comparable. Norepinephrine (P less than 0.01) and epinephrine (P less than 0.001) were higher in diabetics. A hypothesis is formulated that the higher indices of flow velocities in type 1 diabetics are supported by a sympathetic overactivity.

Adult↗
PubMed1990

[Heart function (angioscintigraphic evaluation) and sympathetic tone in insulin-dependent diabetes mellitus].

Cardiac failure is a frequent feature in diabetic patients and it often causes their death. But how and when cardiac disease begins in this kind of patient is still debatable. For example, cardiac failure can be present even in the absence of atherosclerotic involvement of coronary arteries in young diabetics. The aims of our study were to evaluate the cardiac function and sympathetic tone of 16 young type 1 diabetic patients (8 M and 8 F, mean age: 27 years, SD +/- 5) in comparison with 10 normal subjects (4 M and 6 F, mean age: 30 years, SD +/- 7). Diabetic patients were choose from a large population because of the following features young age, absence of clinical and instrumental evidence of micro- or macroangiopathy, clinical evidence of diabetic autonomic neuropathy, proteinuria or arterial hypertension. They were in good metabolic control on daily insulin therapy of two or three administrations. Cardiac function was evaluated at rest and during submaximal exercise on a cycloergometer in supine position using radionuclide ventriculography with technetium 99m. Sympathetic tone was checked using the five clinical tests according to Ewing and the plasmatic level of catecholamines at rest was evaluated using high pressure chromatography. The ejection fraction, cardiac output, stroke volume of diabetics were comparable with those of normal subjects even in the presence of comparable systemic vascular resistance. The increase in ejection fraction during effort was normal. Only in one diabetic patient (incidentally the oldest one) did ejection fraction decrease (7%) during effort. The peak ejection and filling rates were significantly higher (p less than 0.001) in diabetic patients compared to those of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Role of purinergic system in tracheobronchial reactivity of healthy and bronchopathic subjects.

We have investigated the effect of inhaled adenosine on bronchomotor tone in 16 healthy and 24 allergic and non-allergic bronchopathic subjects. We determined the inhaled adenosine dose-response curves after no treatment and after treatment with aminophylline (240 mg in 10 min), reproterol (90 mcg in 2 min) and salbutamol (100 mcg in 2 min) administered intravenously 15 min before adenosine and reproterol (500 mcg) and salbutamol (200 mcg) administered by inhalation from a metered aerosol 30 min before adenosine on separate days. Without prior treatment, inhaled adenosine caused bronchoconstriction in both groups of subjects (normal, and atopic and non-atopic asthmatic ones), but the peripheral airways revealed only a moderate change in normal subjects. Aminophylline caused a greater inhibition of adenosine bronchoconstriction than did reproterol. These results suggest that inhaled adenosine bronchoconstriction involved purinergic transmission and that it is mediated via a P1/Ri (A-1/R1) receptor. Aminophylline is a potent antagonist at purinoceptor level. Reproterol inhibits bronchoconstriction by a mechanism independent of its effect on beta-adrenergic receptors. Because salbutamol, i.e. a beta 2-agonist bronchodilator, did not inhibit adenosine-induced bronchoconstriction (or very nearly so), our results support the view that reproterol antagonizes P1/Ri (A1/R1) tracheobronchial receptors.

Adenosine↗
PubMed1989

Evidence of muscarinic receptor subtypes in airway smooth muscle of normal volunteers and of chronic obstructive pulmonary disease patients.

Since there have been only a few studies on muscarinic receptor subtypes in airway smooth muscle, the effect was investigated of pirenzepine on airways of patients with chronic obstructive pulmonary disease (COPD) and the functional responses compared from these patients with those from healthy subjects. Our data demonstrated that the therapy with pirenzepine significantly improved ventilatory function in patients with COPD. The data also suggested that this drug exerts its action on small airways, but not larger airways in normal subjects. It is possible that in healthy human beings pirenzepine produces mild bronchodilation by means of a vagal efferent blockade, while in patients with COPD, it may be effective because it not only decreases the activity of the vagal efferent pathway, but also decreases the sensitivity of vagal sensory endings and causes a vagal afferent blockade.

Atropine↗
PubMed1989

Muscarinic M-1 receptors mediate the bronchial hyperresponsiveness during methacholine inhalation.

Several data suggest that muscarinic M-1 receptors are located on airway smooth muscle of human beings and dogs. Muscarinic M-1 receptors, whose stimulation is associated with enhancement of acetylcholine release, may also be located in the airway parasympathetic ganglia. To determine if postsynaptic muscarinic M-1 receptors mediate airway constriction, the action was compared of pirenzepine, that antagonizes selectively muscarinic M-1 receptors, and atropine, that blocks both muscarinic M-1 and M-2 receptors, on bronchial responses to methacholine inhalation in seven asthmatic patients. Pirenzepine and atropine gave protection against methacholine; however, the degree of protection by pirenzepine was significantly less than that given by atropine. Some inhibitory effect was obtained in all the patients studied after pirenzepine administration, even though some patients were only slight responders. The significant finding of the study is that pirenzepine partially inhibits the bronchospastic response to methacholine. This result suggests that muscarinic receptors on airway smooth muscle are also of the M-1 subtype.

Administration, Inhalation↗
PubMed1989

Prenatal and postnatal vanadium exposure in rats: effect on vasomotor reactivity development of pups.

The study has been carried out on albino rats pre and/or postnatally exposed to vanadate (1 and 10 mg/dl). In pups pre- and postnatal or postnatal vanadate exposure significantly decreased on the 30th and 60th day of age the pressor response to 1-noradrenaline, and increased the pressor response to sinus-carotid baroreceptor stimulation and the hypotensive responses to 1-isoprenaline and acetylcholine. The effects were observed at vanadate doses that did not interfere with gestation, maternal and pup body weight, maternal systolic arterial blood pressure during pregnancy, and pup systolic arterial blood pressure. These doses have not determined any macroscopic teratogenic effects.

Animals↗
PubMed1987

Prenatal and postnatal antimony exposure in rats: effect on vasomotor reactivity development of pups.

Pregnant female rats were exposed to antimony trichloride (0.1 and 1 mg/dl in their drinking water ad libitum) from the first day of pregnancy until weaning (22nd day after delivery). Pups were exposed to antimony trichloride (0.1 and 1 mg/dl in their drinking water ad libitum) from 22nd until 60th day of age. Antimony exposure did not significantly affect maternal and pup systolic arterial blood pressure, length of gestation, and number of newborn per litter. Antimony exposure decreased maternal and pup body weight. No macroscopic teratogenic effects have been observed. Whether or not pups were exposed to antimony trichloride, pressor responses to carotid occlusion and 1-noradrenaline and hypotensive responses to 1-isoprenaline and acetylcholine were significantly higher on the 60th than on the 30th day of age. In pups, prenatal and postnatal antimony exposure did not affect pressor response to carotidal occlusion, while it decreased pressor response to 1-noradrenaline and hypotensive response to 1-isoprenaline on the 60th day after birth. At last, antimony exposure at higher concentration decreased pup hypotensive response to acetylcholine on the 60th day.

Animals↗
PubMed1984

On the hypolipemic properties of bendaline.

Bendaline, like tiadenol, clofibrate and clofibric acid generally inhibits: a) some hyperlipemias and lipoidoses induced by either an increased exogenous supply of lipids or the stimulation of cholesterol synthesis or mobilization of lipids; b) platelet aggregation in vitro.

Animals↗
PubMed1983

Research on heterocyclic compounds. XIV - Imidazothiazole and imidazobenzothiazole derivatives: synthesis and antiinflammatory activity.

A group of ethyl 6-methylimidazo[2,1-b]thiazole-5-carboxylates and 2-methylimidazo[2,1-b]benzothiazole-3-carboxylates was prepared by reaction of ethyl 2-chloroacetoacetate with some 2-aminothiazoles and 2-aminobenzothiazoles, respectively. Such reactions may sometimes afford a side product which was isolated and characterized. The ethyl esters were then converted into the corresponding acids by hydrolysis. Three of these acids were evaluated for antiinflammatory, analgesic, and antipyretic activities, as well as for ulcerogenic potential.

Animals↗
PubMed1982

Interactions between inosine and adenosine: experimental researches.

Experimental investigations have shown that inosine enhances purinergic reactivity. This was examined with adenosine at the level of the cardiovascular, intestinal and uterine musculature. The mechanism of this activity may probably be inhibition of uptake without significantly altering serum adenosinase.

Adenosine↗
PubMedDate not supplied

Role of nitric oxide on cholinergic component of bronchial tone in pig.

In vitro studies demonstrated that stimulation of intrinsic nerves of airway smooth muscle results in a predominantly contractile response, followed by a relaxant response which involves cholinergic, adrenergic and non-adrenergic non-cholinergic (NANC) nerve activation. Thus, in this paper it is determined whether endogenous nitric oxide (NO) modulates cholinergic neurotransmission in isolated pig airway smooth muscle. Bronchial rings were suspended in organ baths for isometric measurement of tension and the contractions were induced using electrical field stimulation (EFS) techniques. Then, the effects of L-NG-nitroarginine (L-NOARG, 10 microM), an inhibitor of NO synthase, and L-arginine (L-ARG, 1 mM), a precursor of NO synthesis, were evaluated. The cholinergic contractions induced by electrical field stimulation (EFS: 60 V, 2 ms, 60 Hz) of pig lobar bronchial preparations increased (29%) in the presence of L-NOARG (10 microM). This effect may be released by nerves in pig large airways during EFS.

Animals↗
PubMedDate not supplied

Effect of the selective 5-HT2 antagonist ketanserin on adenosine-induced bronchoconstriction in asthmatic subjects.

In eight asthmatic subjects a randomized, double-blind, placebo controlled study was performed to investigate the effect of inhaled ketanserin, a 5-HT2 receptor blocking agent, in a dose of 10 mg given 30 min before test, on adenosine-induced bronchospasm. The protective effect of ketanserin was significant in all patients, even though it altered basal bronchomotor tone in only two subjects. On the contrary, ketanserin did not inhibit histamine-induced bronchoconstriction in four of these eight asthmatics, even though it modified sensitivity and reactivity in one of them. The results suggest that ketanserin influence on adenosine bronchial reactivity and sensitivity was not due to the bronchodilator effect of ketanserin itself or to its antihistaminic activity. We have no certain explanation for the inhibition of adenosine-induced bronchoconstriction elicited by ketanserin. It is possible that 5-HT may play, at least in part, a role as mediator of adenosine-induced bronchoconstriction.

Adenosine↗
PubMedDate not supplied

An acute bronchodilator test with tiotropium or salmeterol does not allow a subdivision of patients according to responses.

BACKGROUND: The possibility that individual chronic obstructive pulmonary disease (COPD) patients respond better to either tiotropium or salmeterol has been suggested and an acute bronchodilator test might help to guide the choice of therapy. OBJECTIVES: We explored the responses to tiotropium and salmeterol within the first 3 h using the recommended dosages (18 microg for tiotropium and 50 microg for salmeterol) in order to verify whether there are differences in the short-term bronchodilator effects between these two long-acting bronchodilators in patients with stable COPD. Moreover, we investigated whether these differences could discriminate between the two agents. METHODS: Forty consecutive patients with COPD, but in a stable phase of the disease, participated in this double-blind, double-dummy, randomized crossover study. The study involved a screening visit and 2 study days separated by at least 1 week. For determination of the onset of action, we measured FEV1 at 10, 20, 30, 60 and 90 min, and again 2 and 3 h after inhalation of single study drug. RESULTS: At all time points, both tiotropium and salmeterol caused significant (p< 0.001) changes from baseline. A mean increase of 12% above baseline was reached 66 min (95% CI: 45-87) after tiotropium and 59 min (95% CI: 41-77) after salmeterol. Nine patients after tiotropium and 5 patients after salmeterol did not have this type of improvement. A mean increase of 200 ml above baseline was reached 76 min (95% CI: 52-101) after tiotropium and 76 min (95% CI: 52-100) after salmeterol. Eighteen patients after tiotropium and 15 patients after salmeterol did not have this improvement. Twenty-one patients after tiotropium and 24 patients after salmeterol reached an improvement that was at the same time 12% and 200 ml greater than baseline. CONCLUSIONS: These data clearly show that the bronchodilator effects of tiotropium and salmeterol within the first hours after their acute administration are similar in patients with stable COPD when they are evaluated as mean changes from baseline in FEV1. Therefore, they question the direct therapeutic relevance of a subdivision of patients according to bronchodilator responses to tiotropium or salmeterol.

Administration, Inhalation↗