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Biomedical subjects

A Bertolini

Publications and source records attributed to A Bertolini.

At least 127 records · Page 7Linked to original sources
PubMed1993

Role of neuronal and vascular Ca(2+)-channels in the ACTH-induced reversal of haemorrhagic shock.

1. In a rat model of volume-controlled haemorrhagic shock causing the death of all control (saline-treated) animals within 30 min, the intravenous (i.v.) bolus injection of ACTH-(1-24) at a dose of 160 micrograms kg-1 produced an impressive and sustained restoration of arterial pressure, pulse pressure and respiratory function, with 100% survival at the end of the observation period (2 h). 2. Both intracerebroventricular (i.c.v., 0.015-0.06 microgram kg-1) and i.v. (5 micrograms kg-1) pretreatment with the N-calcium channel blocker, omega-conotoxin GVIA, and i.v. (but not i.c.v.) pretreatment with the L-calcium channel blocker, nicardipine (125-500 micrograms kg-1) dose-dependently prevented the ACTH-induced shock reversal. 3. These results further indicate that the effect of ACTH in haemorrhagic shock may involve a neuronal link and the eventual restoration of vascular tone mediated by N- and L-type calcium channels, respectively.

Adrenocorticotropic Hormone↗
PubMed1993

Effects of chronic treatment with phenazone on the hot-plate test and [3H]serotonin binding sites in pons and cortex membranes of the rat.

Many reports indicate that nonsteroidal anti-inflammatory drugs exert their antinociceptive effect through adrenergic and serotoninergic systems. We investigated the acute and chronic effects of phenazone on the pain threshold and on brain serotonin binding sites. A relationship between phenazone serum levels and the antinociceptive effect was found; acute treatment with phenazone provokes a significant decrease in serotonin binding sites both in the pons and cerebral cortex after 2, 4 and 8 h, but not after 24 h. After 15 and 30 days of treatment, the number of binding sites increases both in the pons and cortex.

Animals↗
PubMed1993

Hepatitis C in childhood: epidemiological and clinical aspects.

Hepatitis C virus (HCV) is responsible for most cases of chronic non-A, non-B hepatitis in multi-transfused children, but has been also implicated in at least one third of cases without history of parenteral exposure. We have recently evaluated the natural history of chronic hepatitis C in 37 children without underlying systemic diseases. None of the patients had a history of acute hepatitis and only 22 were symptomatic at presentation. Liver histology was consistent with active liver disease of mild to moderate activity in 42% of cases (one child had cirrhosis) and with persistent or lobular hepatitis in the remaining cases. During a mean follow-up period of 3.4 +/- 3.2 years symptoms were rarely observed and none of the patients developed liver failure, but 97% maintained abnormal alanine-aminotransferase levels. These results suggest that chronic hepatitis C in children, at least in its early stage, is a mild disease infrequently associated with severe liver lesions; however the persistence of liver damage over the years raises questions about the long-term outcome of the illness and about the rationale of antiviral therapy.

Acute Disease↗
PubMed1992

Capsaicin prevents the adrenocorticotropin-induced improvement of cardiovascular function and survival in hemorrhage-shocked rats.

A volume-controlled hemorrhagic shock was produced in anesthetized rats by intermittent bleeding from an iliac vein over a period of 20-30 min, until the carotid mean arterial pressure (MAP) stabilized around 20-24 mmHg. In this condition, which caused the death of all saline-treated animals within 25-30 min, the intravenous (i.v.) bolus injection of the adrenocorticotropin fragment 1-24 (ACTH(1-24)) at a dose of 160 micrograms/kg promptly restored MAP, as well as pulse pressure, heart rate and respiratory function, and greatly prolonged the survival time. Capsaicin (125 mg/kg cumulatively, s.c., 1 week before) completely prevented the anti-shock effect of ACTH(1-24), which, on the other hand, was shared by i.v. [Nle11]-substance P (SP) (200-300 micrograms/kg). Finally the SP-antagonist [D-Arg1,D-Pro2,D-Trp7,9,Leu11]-SP prevented the effect of ACTH(1-24). These results suggest that SP-containing nerve fibers are required for the effect of ACTH in hemorrhagic shock.

Adrenocorticotropic Hormone↗
PubMed1992

Reversal of experimental hemorrhagic shock by dimethylphenylpiperazinium (DMPP).

In a rat model of hemorrhagic shock which caused the death of all control rats within 30 min, i.v. injection of the ganglion-stimulating drug dimethylphenylpiperazinium (DMPP) caused a dose-dependent reversal of the shock condition--without the need for reinfusion of the shed blood--starting from the dose of 4 ng/kg i.v. Shock reversal was associated with the mobilization of residual blood and improvement in blood flow, particularly at the carotid level. These results could influence our thinking on pathophysiology and first-aid management of shock.

Animals↗
PubMed1992

Left ventricular function after reversal of myocardial hypertrophy in systemic hypertension, and response to acute increase of afterload by cold pressor test.

Using digitized M-mode echocardiography, the left ventricular (LV) response to acute increase in blood pressure after regression of myocardial hypertrophy due to an effective antihypertensive treatment was evaluated. Fifteen hypertensive patients with basal LV hypertrophy (LV mass greater than 230 g, and normal LV diastolic diameter) and normal LV mass after 3 to 4 months of treatment with angiotensin-converting enzyme inhibitors were selected for study. Subjects performed a cold pressor test before and after therapy. LV systolic function was normal in all subjects. LV diastolic function (impaired at basal evaluation in 13 subjects) improved after therapy in all subjects, with normalization in 10. Before treatment, the cold pressor test induced significant increases in blood pressure and heart rate without changes in LV parameters. After regression of hypertrophy, the cold pressor test induced increases in hemodynamic parameters comparable to those of the basal test, and LV parameters remained unchanged. Our results indicate that regression of myocardial hypertrophy induced by angiotensin-converting enzyme inhibitors does not impair the ability of the left ventricle to face acute increases in afterload. The improvement in LV diastolic function (found at rest after reversal of hypertrophy) persists during the cold pressor test, which confirms that it is primarily due to LV mass reduction and is not simply a consequence of decrease in afterload induced by treatment.

Adult↗
PubMed1992

Galanin inhibits sexual behavior in male rats.

Intracerebroventricular injection of galanin potently inhibited (0.5 micrograms/rat) or completely suppressed (5.0 micrograms/rat) copulatory activity in sexually experienced male rats, without producing any other obvious behavioral deficit. It is suggested that galanin, known to potently stimulate feeding behavior, may be involved in the inverse modulation of feeding and sexual behaviors.

Animals↗
PubMed1992

Sustained AIDS education campaigns and behavioural changes in Italian drug abusers.

In the area of Padua, northern Italy, fear of AIDS along with AIDS educational campaigns had reduced risk behaviours for HIV among intravenous drug abusers (IVDA) as early as 1987, although at that time 38% of seropositive cases still shared needles and only 22% of subjects used condoms. The present study has been conducted in the same area and with similar criteria to evaluate the effectiveness and limits of a sustained education campaign. Drug related and sexual risk behaviours and motivations preventing behavioural changes were investigated by direct interview in 190 IVDA. Fourteen percent of the participants, including 16% of the seropositive, were still sharing needles, mainly because they did not have works available at the time they were needed. Demographic features, drug-related characteristics and anti-HIV seroprevalence did not differ significantly between needlesharers and other drug abusers. Condom use was reported by 46% of subjects, but encouragingly enough this figure included 80% of the seropositives. While knowledge of seropositivity seemed to encourage condom use, a higher selectivity about partners and a negative attitude towards condoms were the most frequent motivations preventing safer sex. These results suggest that sustained AIDS education campaigns are being successful in maintaining and reinforcing the trend to risk reduction previously observed among drug abusers in this area. Nevertheless the persistence of risk behaviours in a consistent proportion of participants emphasizes the urgency of additional prevention strategies, such as syringe exchange or supply to the limited number of sharers and counselling to encourage safer sex.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Pinacidil potentiates morphine analgesia.

The opening of K+ channels in the membrane of target neurons is a key mechanism of the effect of opioids. Here we show that the K+ channel opener, pinacidil, i.c.v. injected at doses of 50, 100 or 150 micrograms/rat, significantly increases and prolongs the effect of morphine on the thermal pain threshold (hot-plate and tail-flick tests). These data may suggest a novel approach to the management of pain.

Analgesia↗
PubMed1992

Repeated administration of triiodothyronine enhances the susceptibility of rats to isoniazid- and picrotoxin-induced seizures.

In an experimental condition of hyperthyroidism, obtained by repeated administration of triiodothyronine in adult rats (100 micrograms/kg/day, sc for 7 consecutive days), there is an increased susceptibility to the convulsant effect of isoniazid (300 mg/kg, ip) and picrotoxin (4 mg/kg, ip). On the other hand, the characteristics of brain [3H] flunitrazepam binding sites are not modified. These data afford further experimental evidence of the influence of thyroid hormones on brain function.

Animals↗
PubMed1992

Influence of CRF and alpha-MSH on the migration of human monocytes in vitro.

The effects of stress in the modulation of immune responses are increasingly reported by a rapidly growing body of experimental and clinical data. Here we show that corticotropin releasing factor (CRF) stimulates 'in vitro' the migration of human monocytes, the maximum effect being obtained at 10(-14) M. On the other hand, another important neuropeptide of the stress response, alpha-melanocyte stimulating hormone (alpha-MSH), has no significant effect on the migration of monocytes. These findings show that one of the oldest immune responses is directly modulated by a key mediator of the stress response.

Chemotaxis, Leukocyte↗
PubMed1992

Behavioral effects of atriopeptin in rats.

High densities of atriopeptin-immunoreactive fibers and of highly specific and selective atriopeptin receptor sites are present in brain areas involved in animal behavior. The possible influence of these peptides on behavior was thus investigated in adult rats. The intracerebroventricular injection of atriopeptin II modified male sexual behavior (reduction in mount latency) at the dose of 5 micrograms/animal; lower and higher doses were ineffective. Open-field behavior was also modified by i.c.v. atriopeptin II at the doses of 5 and 10 micrograms/rat, which induced an increase in the number of external and internal crossings and of external rearings. Finally, in fasted rats, atriopeptin II, at the dose of 10 micrograms/rat, significantly increased the amount of food intake 30 and 60 min after injection. These findings indicate that atriopeptins may modify different animal behaviors.

Animals↗
PubMed1992

[Castleman's disease. A clinical case].

Castleman's disease is an uncommon lymph node syndrome. It is usually a lymphoid hamartoma, rarely systemic. We report a case of Castleman's multicentric disease observed in our hospital and review the literature. In this work we review prognosis, follow-up and therapy of 46 multicentric disease reported in the literature.

Castleman Disease↗
PubMed1991

Ischemia- and reperfusion-induced arrhythmias are prevented by putrescine.

The influence of putrescine on cardiac arrhythmias induced by either permanent ligature of the left anterior coronary artery or heart reperfusion following a 5-min coronary occlusion was studied in anesthetized rats. Reperfusion-induced arrhythmias were significantly prevented by the i.v. injection of 150-200 mg/kg of putrescine, the survival rate being 100% in treated animals and 40% in controls. At a dose level of 200-300 mg/kg i.v., putrescine also significantly reduced the duration of ventricular tachycardia induced by permanent coronary occlusion. These findings show that putrescine significantly reduces the consequences of cardiac ischemia and reperfusion, probably as a consequence of its multiple stabilizing effects at the membrane level.

Anesthesia↗
PubMed1991

Nicotine reverses hemorrhagic shock in rats.

Cholinergic mechanisms are currently thought to play an essential role in blood pressure homeostasis. Here we show that, in urethane-anaesthetized rats bled to severe hemorrhagic shock, the i.v. administration of nicotine 0.2-50 micrograms/kg causes a prompt, sustained and dose-dependent improvement in cardiovascular and respiratory functions, the animals' survival rate being significantly higher than that of animals treated with saline. These effects are prevented by bilateral cervical vagotomy and by concurrent local anaesthesia of the carotid bodies, which suggests that stimulation of visceral afferents is the main mechanism of action of nicotine in hemorrhagic shock.

Animals↗
PubMed1991

TRH reverses the ECG and EEG ischemic changes induced by massive hemorrhage in rats.

In a rat model of volume-controlled hemorrhagic shock causing the death of all saline-treated animals within 30 min of treatment, the intravenous bolus injection of thyrotropin- releasing hormone tartrate (TRH-T) at the dose of 4 mg/kg induced the prompt and sustained disappearance of the ECG and EEG signs of heart and brain ischemia, along with the reversal of hypotension and respiratory depression and with 100% survival rate at the end of the 2 h observation period. These data confirm that, in a pre-terminal condition induced by massive hemorrhage, timely treatment with TRH-T will restore heart and brain perfusion to levels compatible with survival and with functional recovery from ischemia and maintain it at those levels for some hours.

Animals↗