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Biomedical subjects

A Bertolini

Publications and source records attributed to A Bertolini.

At least 181 records · Page 10Linked to original sources
PubMed1988

Early treatment of patent ductus arteriosus in premature infants with severe respiratory distress syndrome.

In 1983, a US National Collaborative Study (NCS) proposed criteria for the diagnosis of hemodynamically significant patent ductus arteriosus (PDA) in premature infants with respiratory distress syndrome (RDS), but the widespread use of pulsed Doppler cross-sectional echocardiography (PD-CSE) in neonatal intensive care units has made direct assessment of the ductus possible thus providing more timely therapy. We have compared the results in 30 premature infants with severe RDS, assessed according to the guidelines of the US NCS, with those in 51 infants whose PDA was diagnosed by PD-CSE. Together with a significant reduction in the age at treatment (7.8 +/- 3.9 vs 2.4 +/- 1.1 days), there was a reduced dependence on artificial ventilation (14.8 +/- 11.0 vs 7.8 +/- 2.7 days), a reduction in the number requiring surgical ligation of PDA (9 vs 2), a decreased incidence of bronchopulmonary-dysplasia (BPD) (40% vs 16%), and a reduction of unfavorable outcome of treatment (death or BPD) (76% vs 49%).

Bronchopulmonary Dysplasia↗
PubMed1988

Improved recovery of nigro-striatally hemitransected rats induced by (Nle4, D-Phe7)alpha-MSH: a central effect.

Rats were subjected to nigro-striatal hemitransection and then intracerebroventricularly infused with the potent and long-acting alpha-MSH analogue, (Nle4, D-Phe7)alpha-MSH, at two different doses (15 or 30 ng/h/rat), or with saline (0.6 microliter/h/rat), continuously for 14 days starting on day 2 after lesion. (Nle4, D-Phe7)alpha-MSH dose-dependently improved the sensorimotor deficit (postural asymmetry, impaired limb reflexes and coordinated limb use, signs of cortical and pyramidal lesion), reduced turning behaviour induced by apomorphine, and increased spontaneous motility in the open field. 3H-Spiperone binding showed that (Nle4, D-Phe7)alpha-MSH treatment caused a down regulation of the striatal DA receptors in the lesioned side, contrary to the supersensitivity developed by the corresponding receptors of saline treated rats. These results indicate that melanopeptides improve the functional recovery of nigro-striatally hemitransected rats, by an action at CNS level.

Animals↗
PubMed1988

Anti-shock effect of ACTH-(1-24): influence of subtotal hepatectomy.

Subtotally hepatectomized or sham-operated rats were bled to hypovolemic shock (mean arterial pressure = 18-25 mmHg) and then treated with an intravenous bolus injection of ACTH-(1-24), 160 ug/kg. The treatment caused a prompt and sustained reversal of hypotension, with survival of all sham-operated animals, at least for the first 2 h, while in hepatectomized rats the arterial pressure increase was negligible and there was a 50% mortality within 2 h after treatment. Moreover, the blood volume which could be drained from an arterial catheter prior to death, measured 15-20 min after ACTH injection, was 1.51 +/- 0.12 and 0.64 +/- 0.11 ml/100 g b.w. in sham-operated and hepatectomized rats, respectively. These results further support the idea that the effect of ACTH in haemorrhagic shock is due to the mobilization of blood pooled in peripheral reserve organs.

Animals↗
PubMed1988

Treatment with polyamine synthesis inhibitors reduces the positive inotropic effect of ouabain, noradrenaline and calcium.

Polyamines (putrescine, spermidine and spermine) are considered to act as intracellular second messengers by increasing Ca++ influx and mobilizing intracellular calcium. On the other hand, intracellular Ca++ increase is the common final step of the mechanism of action of many inotropic agents. To discover whether the functional integrity of the cardiac ornithine decarboxylase (ODC)/polyamine system is necessary to cope with a stimulated inotropism, we studied the effect of ouabain, noradrenaline, and calcium on ventricle strips obtained from rats treated with polyamine synthesis inhibitors. The combined administration of methylglioxal bis (guanylhydrazone) (MGBG) (single i.p. injection of 50 mgkg-1) and of alpha-di fluoromethylornithine (DFMO) (100 mgkg-1 every 12 h for 7 consecutive days) caused a 62.5% inhibition of ventricular ODC activity, and a significant decrease of the ventricular content of putrescine and spermidine (-59.5%, and -40.1%, respectively). While the basal isometric tension developed by ventricle strips obtained from rats treated with MGBG+DFMO was similar to that developed by ventricle strips from controls, the response to ouabain (1 microM), noradrenaline (10 microM), or Ca++ (3.6 mM) was significantly reduced. It cannot be excluded that effects of MGBG unrelated to the inhibition of polyamine synthesis may have also concurred in part to influence the effect of ouabain, Ca++ and noradrenaline adversely. However, the present results seem to indicate that the heart response to inotropic agents requires an efficient ODC/polyamine system, polyamines probably being involved in calcium ion movements or affecting the Ca++ sensitivity of contractile proteins.

Animals↗
PubMed1988

Influence of the intravenous administration of ACTH-(1-24) on the characteristics of brain, heart and spleen adrenoceptors of haemorrhage-shocked rats.

Urethane-anesthetized rats were bled to otherwise irreversible haemorrhagic shock (mean arterial pressure = 18-25 mmHg) and then i.v. treated with ACTH-(1-24) (160 micrograms/kg) or saline. In comparison with sham-operated, non-shocked controls, bled rats showed a significant reduction in Bmax for [3H]Dihydroalprenolol and [3H]Dihydroergocryptine in heart ventricles, and for [3H]Yohimbine in spleen capsule. Neither the Kd of heart and spleen adrenoceptors nor the Bmax or Kd of brain adrenoceptors were affected. Treatment with ACTH-(1-24) restored to normal the Bmax for [3H]Dihydroalprenolol in heart ventricles, and for [3H]Yohimbine in the spleen capsule. These data indicate that the anti-shock effect of ACTH-(1-24) in bled rats is associated with a restoration of heart and spleen responsiveness to adrenergic stimuli.

Animals↗
PubMed1988

Mechanism of action of the anti-shock effect of CCK-8: influence of CCK antagonists and of sympatholytic drugs.

In an experimental model of haemorrhagic shock that causes 100% mortality in rats within 30 min, the intravenous bolus injection (20 micrograms/kg) of sulfated cholecystokinin octapeptide (CCK-8) induces a prompt and sustained rise in blood pressure and pulse amplitude, all treated animals still surviving at the end of the experiment (2 h). This effect of CCK-8 is completely blocked by reserpine (5 mg/kg i.p.), significantly antagonized by prazosin (0.1 mg/kg i.v.) and yohimbine (1 mg/kg i.v.), and unaffected by practolol (15 mg/kg i.v.) and proglumide (0.2 mg/kg i.v.); it is completely antagonized by the intravenous (0.01-0.05 mg/kg), but not by the intracerebroventricular (0.002 mg/kg) injection of the 'peripheral' CCK antagonist, L-364,718. The present data indicate that the cardiovascular effects of CCK-8 in haemorrhagic shock involve peripheral CCK receptors, and require the functional integrity of the sympathetic nervous system.

Animals↗
PubMed1988

[Percutaneous transluminal laser angioplasty. Initial clinical experience in 9 patients].

In this paper the authors report on a new technique--percutaneous transluminal laser angioplasty (PLR) which was performed on 9 patients with iliac and/or femoro-popliteal artery occlusion. All patients were males (mean age: 64.5 years) and had arterial occlusion (mean length: cm 12.5). PLR was performed with an argon laser (max power: 16 Watts). In 8 out of 9 patients (88.8%) a complete recanalization was obtained of the occluded arterial tract, without complications. In one case only (12.2%) there was an arterial wall perforation with unsatisfactory results. In our opinion, PLR has proven a simple methodology, which can be performed on any patient due to the very low incidence of severe complications and distal embolism. Moreover, PLR has quite low costs, and does not prevent eventual surgical/percutaneous interventions.

Aged↗
PubMed1987

Enzymuria in carboplatin nephrotoxicity.

Urinary excretion of N-acetyl-beta-glucosaminidase (NAG) is an early marker of nephrotoxicity. NAG activity was assayed by the fluorimetric method of Leaback and Walker in 17 patients treated (22 courses) with carboplatin (CBDCA, 220-550 mg/m2) before infusion and 24, 48, 72 and 96 h after. Increased excretion of NAG, a sensitive index of renal tubular damage, was observed following 10 of the 22 courses. A transient increase in plasma creatinine and/or abnormal proteinuria was observed in 6 cases. Impaired renal function prior to therapy seems to be a predisposing factor to the nephrotoxicity.

Acetylglucosaminidase↗
PubMed1987

Oxytocin acts as an antidepressant in two animal models of depression.

In the behavioral despair test in mice, oxytocin, i.p. injected 60 min before testing, significantly reduced the duration of immobility at doses of 0.250-1.0 mg/Kg; the effect being similar to that of imipramine (7.5-30 mg/Kg i.p.). A more powerful effect was obtained with a 10-day treatment schedule. In the learned helplessness test, oxytocin (0.500 mg/Kg/day i.p. for 8 days) significantly reduced the escape failures and the latency to escape, the effect being even more intense than that of imipramine (20 mg/Kg/day i.p. for 8 days). These results show a new behavioral effect of oxytocin, and further support its role of CNS regulatory peptide.

Animals↗
PubMed1987

Anti-shock effect of ACTH-(1-24) in rats: comparison between intracerebroventricular and intravenous route of administration.

In an experimental model of hypovolemic shock in rats, produced by withdrawing about 50% of the estimated total blood volume, and causing 100% deaths within 30 min, ACTH-(1-24) dose-dependently improved arterial and pulse pressure and increased survival rate. The intracerebroventricular (i.c.v.) route of administration was more effective than the intravenous (i.v.) route: at the dose of 24 micrograms/kg, 45% and 91% of rats were still surviving 2 hr after i.v. and i.c.v. treatment, respectively. At higher doses of ACTH-(1-24), the survival rate rose to 100% regardless of the route of administration, but arterial pressure increased more after i.c.v. than after i.v. injection. These data suggest that the CNS plays an important role in the anti-shock effect of ACTH.

Adrenocorticotropic Hormone↗
PubMed1987

Different cholinergic pathways are involved in the improvement induced by CCK-8 and by ACTH-(1-24) in massive acute hemorrhage, in rats.

Cholecystokinin octapeptide (CCK-8) (20 micrograms/kg i.v.) and tetracosactide [ACTH-(1-24)] (160 micrograms/kg i.v.) restore blood pressure and allow rats subjected to otherwise invariably fatal acute hemorrhage to survive. Atropine sulphate (2-8 mg/kg i.p.), which crosses the blood-brain barrier, dose-dependently prevents this effect both in the case of ACTH-(1-24) and in that of CCK-8. On the other hand, atropine methyl bromide (2-8 mg/kg i.p.), which does not cross the blood-brain barrier, prevents the effect in the case of CCK-8, but not in that of ACTH-(1-24). These data suggest that a cholinergic mechanism is involved in the anti-shock effect of both ACTH-(1-24) and CCK-8, though the sites of action appear to be in the CNS, in the case of ACTH-(1-24), and outside the CNS, in that of CCK-8.

Animals↗
PubMed1987

Acute alkalosis, but not acute hypocalcemia, increases panic behavior in an animal model.

Non-pretrained, randomized adult rats were tested in a panic-inducing model of passive avoidance. Intravenous treatment with alkalinizing agents (sodium lactate 0.5 M, 0.5 ml/100 g b.wt., or NaHCO3, 0.5 mEq/100 g b.wt.), but not with a hypocalcemic dose of EDTA (75 mg/kg) 3 min before testing, significantly increased panic behavior. These data may support the hypothesis that panic attacks are due to alkalosis and not to lactate-induced hypocalcemia.

Alkalosis↗
PubMed1987

Influence of protease inhibitors on the antidepressant activity of oxytocin.

Both in the behavioral despair test and in the learned helplessness test, the antidepressant-like activity of oxytocin (0.500 mg/Kg i.p.) was prevented by the administration of a protease inhibitor (EACA, 400 mg/Kg i.p.; pepstatin, 0.1 mg/Kg i.p.). On the other hand, the linear tripeptide tail of oxytocin, MIF-1, was inactive in the behavioral despair test, and less active than oxytocin in the learned helplessness test. We conclude that the antidepressant activity of oxytocin is due to its cleavage to some smaller fragment(s) different from MIF-1.

Animals↗
PubMed1987

Prenatal ultrasonic detection of truncus arteriosus with interrupted aortic arch and truncal valve regurgitation.

The echocardiographic appearances in a case of persistent truncus arteriosus with aortic arch interruption and truncal valve dysplasia was noted in a 24 week fetus. Elective termination of pregnancy was carried out and all the echocardiographic findings were confirmed by pathological examination suggesting the possibility of accurate prenatal diagnosis of such lesions.

Adult↗