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Biomedical subjects

A Bertolini

Publications and source records attributed to A Bertolini.

At least 217 records · Page 12Linked to original sources
PubMed1986

[Pulsed Doppler in children operated on for aortic coarctation: reliability in the evaluation of minor residual lesions].

The usual non invasive diagnostic methods may not be able to estimate a mild residual gradient in infants treated for Coarctation of the Aorta (CA) so we tried to determine whether Pulsed Doppler (PD) may be useful in these cases. We studied 16 children (Group A) treated for CA, clinically considered as good operative results (arm to leg gradient less than or equal to 10 mmHg) and admitted for cardiac catheterization to study associated cardiac defects. Ten children with congenital heart disease different from CA were studied as a control (Group B). Percutaneous left cardiac catheterization was performed in all children with pull-back recording of the aortic pressure across aortoplasty before angiography. PD study was performed with an ATL Mark 600 and a 3 MHz transducer positioned in the suprasternal notch. The sample volume was moved into the descending aorta in order to obtain peak flow velocity (PFV) and estimate systolic gradient (DEG). Cardiac catheterization gradients (CCG) ranged from 0 to 20 mmHg (3.9 +/- 6.3 mmHg) in Group A while no gradient was recorded at the Isthmus in Group B. In Group A the frequency shift changed just below the aortoplasty; PFV and DEG ranged respectively from 1 to 2.3 m/s (1.6 +/- 0.3 m/s) and from 4 to 22 mmHg (10 +/- 4.8 mmHg). In Group B the descending aorta PFV ranged from 0.8 +/- 1.3 m/s (1 +/- 0.2 m/s). PFV in Group A was higher than in Group B (p less than 0.001). CCG were plotted against DEG; the linear regression gave a satisfactory coefficient of correlation (R = 0.93 and p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Oxytocin improves male copulatory performance in rats.

The role of oxytocin in male copulatory performance was reexamined in rats. Adult male rats were trained seven times for copulatory behavior, at weekly intervals. Oxytocin, either intraperitoneally injected (200 ng/rat) or intracerebroventricularly infused (1 ng/rat in 4 microliter saline) 60 and 5 min, respectively, before the eighth test, significantly shortened both the ejaculation latency and the postejaculatory interval. The intracerebroventricular infusion of saline alone (4 microliter/rat) had no effect at all.

Animals↗
PubMed1985

Characterization of the contractile activity of dopamine on the rat isolated seminal vesicle.

The mechanism of the contractile effect of dopamine (DA) on the rat isolated seminal vesicle was studied. Cocaine (10 microM/1 in the organ bath, 30 min before DA) and 6-OHDA (50 mg/kg i.v. 24 hr before removal of the seminal vesicle) almost completely prevented the contractile effect of DA. Drugs known to have an affinity for DA receptors or for alpha-adrenoceptors antagonized the contractile effect of DA, the rank order of potency being: prazosin greater than phentolamine greater than yohimbine greater than clonidine greater than sulpiride greater than apomorphine greater than haloperidol. The antagonism was in each case greater against DA than against noradrenaline (NA), used for comparison; selectivity for DA being highest in the case of prazosin and sulpiride. Taken together, these findings indicate that DA makes the rat seminal vesicle contract mostly by means of an indirect mechanism, binding presynaptic DA-receptors and, in part, presynaptic alpha-adrenoceptors as well; or, alternatively, binding presynaptic DA-receptors which have some links with alpha 2-adrenoceptors; the consequence being in either case the release of NA from sympathetic nerve endings.

Animals↗
PubMed1985

Metronidazole-quinolone combination: antibacterial activity in vitro.

Combination of metronidazole and oxolinic or pipemidic acid were tested in vitro against some of the bacteria most commonly responsible for genito-urinary infections (E. coli, K. pneumoniae, Enterob. cloacae, Serratia marcescens, Pr. mirabilis, Pr. morganii, Str. faecalis and 3 strains of Ps. aeruginosa). The metronidazole-oxolinic acid combination was found to be additive or synergistic against E. coli, K. pneumoniae, Enterob. cloacae and Serratia marcescens. The results show that subinhibitory concentrations of oxolinic acid may reveal an activity of metronidazole against aerobic and facultative anaerobic bacteria, under aerobic conditions.

Bacteria↗
PubMed1985

Effect of polyamines on perfused rat heart contractility.

The influence of polyamines (putrescine, spermidine and spermine) on heart contractility was studied using perfused rat ventricle strips (2 X 10 mm), electrically driven at 1 Hz. Putrescine (100 microM) caused a negative inotropic effect gradually increasing in intensity, whereas spermidine and spermine (10 and 100 microM) caused a sharp, positive inotropic effect, followed by a rapid and more marked fall. The possibility that these effects of polyamines on heart contractility may be due to their role in Ca++ fluxes and mobilization, and in membrane functions, is discussed.

Animals↗
PubMed1985

Influence of yohimbine on the ACTH-induced behavioural syndrome, in rats.

In adult male rats, yohimbine at low doses (0.1, 0.5 and 1 mg/kg i.p.) potentiated, and at high doses (30.0 mg/Kg) antagonized, the behavioural syndrome induced by the intracerebroventricular injection of ACTH 1-24 (3 micrograms/rat) (stretching-yawning syndrome and penile erections). These results support the hypothesis that brain catecholaminergic systems play a positive role in the ACTH-induced behavioural syndrome.

Adrenocorticotropic Hormone↗
PubMed1985

Oxytocin stimulates lordosis behavior in female rats.

Oxytocin, either intraperitoneally injected (200 ng/rat) or intracerebroventricularly infused (1 ng/rat in 4 microliters saline) 60 and 15 min respectively before testing, significantly increased the lordosis response to the mounting male of ovariectomized, estrogen/progesterone treated rats. The intracerebroventricular infusion of oxytocin 0.1 ng/rat had no effect; nor did saline. These results indicate that oxytocin increases female receptivity, the site of action probably being in the central nervous system.

Animals↗
PubMed1985

Convulsive syndrome induced by the intracerebroventricular injection of alpha-difluoromethylornithine in rats.

In adult rats, the intracerebroventricular injection of alpha-difluoromethylornithine (DFMO), a polyamine antimetabolite which specifically inhibits ornithine-decarboxylase, induces a typical convulsive syndrome (ED50 = 100 micrograms/rat) and death (LD50 = 300 micrograms/rat). Histological lesions are seen only with the highest doses and are essentially restricted to the Ammon's horn neurones. Since DFMO is currently undergoing clinical trials for use in cancer chemotherapy, including brain tumours, its CNS toxicity should be carefully considered.

Animals↗
PubMed1984

Putrescine has analgesic activity, in rats.

Putrescine, intraperitoneally injected into rats at doses of 200, 300 and 400 mg/Kg, had a dose-dependent analgesic effect (hot plate, 55.5 degrees C), which was not antagonized by naloxone. Analgesia was also obtained by intracerebroventricular injection (1,000 nmoles/rat). Chronic administration (300 mg/Kg/day i.p. for 8 consecutive days) resulted in the development of tolerance. In our experimental conditions, no obvious toxicity was observed. These results may suggest for polyamines a role in nociception, and may disclose a new class of analgesic drugs.

Analgesics↗
PubMed1984

Influence of clonidine on the ACTH-induced behavioral syndrome.

In male rats, clonidine in a dose range of 1-3000 micrograms/kg i.p. antagonized the stretching-yawning syndrome induced by the intraventricular injection of ACTH-(1-24) (3 micrograms/rat) dose-dependently. On the other hand, the effect of clonidine on ACTH-induced penile erections was potentiation at low doses (5 and 10 micrograms/kg) and inhibition at the highest doses (1000 and 3000 micrograms/kg), the intermediate doses (50 and 100 micrograms/kg) being without effect. There was no relationship between these behavioral effects and the effect on arterial blood pressure.

Adrenocorticotropic Hormone↗
PubMed1984

Pain threshold and morphine activity in vitamin D-deficient rats.

In rats, vitamin D-deficiency increases basal pain threshold and the analgesic effect of morphine (hot plate test). Cholecalciferol (1000 I.U./Kg/day s.c.x 5 days) restores pain sensitivity in vitamin D-deficient rats and brings the analgesic effect of morphine back to normal. On the other hand, tolerance to morphine develops faster in vitamin D-deficient rats, this effect too being prevented by cholecalciferol treatment. These data suggest a role for vitamin D status in pain sensitivity and opiate activity.

Animals↗
PubMed1984

Sexual behavior of male rats: influence of short- and long-term adrenalectomy.

Adult male rats (3 months old) were tested for their copulatory behavior: those satisfying the criterion of sexual vigor in the last three out of five weekly tests were randomly divided into two groups and adrenalectomized or sham operated, and their copulatory activity was retested 35 and 420 days after surgery. Short-term adrenalectomy did not modify any of the parameters of sexual behavior. On the other hand, a higher percentage of adrenalectomized than of sham-operated rats still had successful sexual performance when 18 months old (420 days after surgery); moreover, blood levels of testosterone were higher in adrenalectomized than in sham-operated old rats. The possibility that adrenal steroids may play a role in the age-linked decline in male sexual activity in mammals is discussed.

Adrenal Glands↗
PubMed1984

Effect of alpha-difluoromethylornithine (DFMO) on the behavioral syndrome induced by intracerebroventricular injection of ACTH 1-24, in rats.

Stretching-yawning syndrome (SYS) and penile erections (PE) are typical components of the behavioral picture induced by intracerebroventricular (i.c.v.) injection of ACTH 1-24. The present study shows that pretreatment with alpha-difluoromethylornithine (DFMO), and irreversible inhibitor of mammalian ornithine decarboxylase (ODC), antagonizes these behavioral effects in a dose-dependent way, in rats. These results suggest that ODC and polyamines may play a role in the transduction and transmission of receptor-mediated signals.

Adrenocorticotropic Hormone↗