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Biomedical subjects

A Bertolini

Publications and source records attributed to A Bertolini.

At least 199 records · Page 11Linked to original sources
PubMed1987

Shaking behaviour induced by putrescine in naive rats: a pharmacological and histological study.

In untreated rats, the intraperitoneal injection of putrescine evoked a typical wet-dog shake response, that was maximal at a dose of 300 mg/kg and at room temperature (22 degrees) (number of shakes: 84.00 +/- 17.90/hr). In a hot environment (30 degrees) the number of shakes was markedly reduced (26.90 +/- 5.19/hr). The putrescine-induced shaking behaviour was unaffected by atropine, bicuculline, chlorpheniramine, cimetidine, methysergide, naloxone and noradrenaline, but was markedly antagonized by morphine. Naloxone pretreatment nullified the antagonistic activity of morphine. Histological studies showed marked alterations in brain vascular permeability, which was increased by putrescine. Morphine completely prevented this putrescine-induced vascular effect. These results suggest a correlation between WDS produced by putrescine and increase in brain vascular permeability. Furthermore they show that morphine can affect brain vascular permeability.

Animals↗
PubMed1987

Bactericidal and antineoplastic effect of combination of norfloxacin and adriamycin.

Norfloxacin and adriamycin were tested alone and in combination for bactericidal activity against different strains of gram-negative bacteria. The antitumoral effect of a combination of norfloxacin and adriamycin was determined in mice bearing Ehrlich ascites carcinoma and in mice bearing P 388 leukemia. No interference with the antibacterial activity of norfloxacin or with the antitumoral activity of adriamycin was observed.

Animals↗
PubMed1987

Anti-shock effect of ACTH: haematological changes and influence of splenectomy.

ACTH-(1-24), injected i.v. into rats subjected to otherwise invariably fatal bleeding, at the dose of 160 micrograms/kg, causes a prompt and sustained increase in mean arterial and pulse pressure, with survival of all treated animals, at least for the first 2 hr. This is associated with a 100% increase in the volume of circulating blood, which is of normal composition, so that also the number of circulating red cells is doubled as compared to controls. Splenectomy greatly impairs the beneficial effect of ACTH on blood pressure, blood volume and survival. It is concluded that, in cases of acute hypovolemia, ACTH-(1-24) induces a recall of blood from storage sites and its redistribution, though the precise mechanism is as yet unknown.

Animals↗
PubMed1987

Extracardiac malformations and congenital heart disease: frequency and patterns of associations.

Congenital Heart Malformations (CHM) can be present together with Extracardiac Malformations (ECM) in a single individual, however the frequency and the patterns of associations are not well defined because the casistics of the literature are little comparable. The diagnosis of CHM has been demonstrated with cardiac catheterization in any case. Between January 1st, 1976 and December 31st, 1983 cardiac catheterization has been performed in 1012 children and 971 of them were affected by Congenital there was at least one ECM as well (group B); 311 ECM were present in group B. VSD (p less than 0.05) and Atrioventricular Septal Defects (AV.SD) (p less than 0.01) resulted associated with ECM while T.F. (p less than 0.05) and isolated TGA (p less than 0.01) showed the tendency to occur in isolation. VDS resulted associated with gastrointestinal anomalies (p less than 0.05), AV.SD with T21 (p less than 0.001), aortic valve (p less than 0.05) and supra-valve (p less than 0.001) stenosis with Nervous System abnormalities. Pulmonary stenosis showed little tendency to occur together with T21 (p less than 0.05).

Abnormalities, Multiple↗
PubMed1986

Alpha-MSH and other ACTH fragments improve cardiovascular function and survival in experimental hemorrhagic shock.

Hypovolemic shock was produced in rats by withdrawing about 50% of the estimated total blood volume. Following mean arterial pressure stabilization in the range of 15-25 mm Hg, with a pulse pressure of 7-12 mm Hg, the rats were given intravenous bolus injections either of ACTH fragments or of saline. The following ACTH fragments or analogs were used: ACTH-(4-10), alpha-MSH, ACTH-(1-16), ACTH-(1-17), ACTH-(1-18), [Nle4,D-Phe7]alpha-MSH, [beta-Ala1,Lys17]ACTH-(1-17)-4-amino-n-butilamide (alsactide). ACTH-(1-24) and human synthetic ACTH-(1-39) were used for comparison. All animals treated with saline died in 22.51 +/- 3.62 min. Treatment with ACTH fragments (160 micrograms/kg i.v.) increased blood pressure and pulse amplitude, the effect starting within a few minutes, gradually increasing, and reaching a maximum in 15-30 min. The blood and pulse pressure increases were sustained, remaining almost stable until the end of the 2 h recording. Two out of nine rats treated with alsactide, which was the least active, died within 2 h after treatment, while all rats treated with the other ACTH fragments or analogs were still surviving at that time. Both on a weight and on a molar basis, the most active was ACTH-(1-24), followed by ACTH-(1-16), by the alpha-MSH analog [Nle4,D-Phe7]ACTH-(1-13), by ACTH-(1-18) and by ACTH-(1-17). The present results show that melanocortins reverse otherwise fatal hypovolemic shock, and suggest a new therapeutic approach for shock treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1986

Adrenocorticotropin reversal of experimental hemorrhagic shock is antagonized by morphine.

ACTH-(1-24) dose-dependently improved cardiovascular function in rats and dogs subjected to experimental hemorrhagic shock, and intravenous dose of 160 and 100/microgram/kg, respectively, completely restoring arterial blood pressure and pulse amplitude. All saline-treated animals died within 30 min of bleeding, while all ACTH-treated animals were still alive at the end of the observation period (2 hr). The injection of ACTH-(1-24) also dramatically improved the respiratory function. Morphine, i.v. injected into rats at the dose of 2.5 mg/kg, antagonised the effect of ACTH-(1-24) to a greater or lesser degree, depending on the dose of peptide employed: at 160/microgram/kg, antagonism was complete, at 320/microgram/kg antagonism was only partial, while at 480/microgram/kg antagonism was almost completely overcome. These data further support the idea that melanocortins are physiological antagonists of opioids, and suggest that melanocortin peptides may prove to be rational and effective drugs in the treatment of hypovolemic shock.

Adrenocorticotropic Hormone↗
PubMed1986

Putrescine has hypothermic and antipyretic activity, in rats.

Intraperitoneal injection of putrescine induced dose-related hypothermia in rats. The effect was more pronounced at room temperature (22 degrees C) than in a warm environment (30 degrees C), the maximum hypothermia (-2.64 +/- 0.29 degrees C, 30 min. after treatment) being obtained with the dose of 300 mg/Kg and remaining significant throughout 3 hr of observation. Putrescine also had antipyretic activity, as it significantly reduced pyrogen-induced fever at a dose level (100 mg/Kg i.p.) ineffective in causing hypothermia in normal rats. The hypothermic and antipyretic effects of putrescine were not associated with any obvious sign of toxicity.

Animals↗
PubMed1986

Morphine and beta-endorphin antagonize posture and locomotor disorders induced by the injection of ACTH 1-24 in the rat locus coeruleus.

The unilateral microinjection of ACTH 1-24 (20 nmol) into the locus coeruleus (LC) produced a long lasting (2-3 hr) posture asymmetry and movement disorder in all rats tested. This response was readily suppressed by the subsequent local microinjection of an equimolar dose of beta-endorphin or morphine or by the intraperitoneal injection of morphine sulphate (50 mg/kg). Microinjection of naloxone (20 nmol) into the LC produced the above syndrome in a lower percentage of animals. The results support the hypothesis that ACTH peptides and opioids play opposite roles in the control of different brain functions.

Adrenocorticotropic Hormone↗
PubMed1986

Griseofulvin-methisoprinol combination in the treatment of herpes zoster.

A total of 57 herpes zoster patients (28 men and 28 women) were randomly assigned to one of the following four treatments: griseofulvin, 125 mg four times daily; methisoprinol, 1 g four times daily; griseofulvin plus methisoprinol (dosage schedules as above); placebo, four times daily. Griseofulvin had no effect at all, methisoprinol both significantly accelerated drying of vesicles and reduced pain, and the combination of griseofulvin and methisoprinol turned out to be significantly more effective in reducing pain than methisoprinol alone. The present results suggest a new effective treatment for herpes zoster disease.

Aged↗
PubMed1986

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↗
PubMed1986

Effects on long-term sensitivity to pain and morphine of stress induced in the newborn rat by pain or manipulation.

Four times daily from postnatal day 1 to 15, rats were stressed either by being removed from the maternity cage (manipulation stress, MS) or by being placed on a hotplate at 55 degrees C (pain stress, PS). When 70 days old, they were examined for sensitivity to pain and to the analgesic effect of morphine, and for brain opiate receptors. Pain sensitivity of MS and PS rats was not significantly different from that of controls. The analgesic activity of morphine, assessed by the hotplate test at 49 degrees C, was significantly reduced in MS rats, while in PS rats it was similar to that in controls. 3H-dihydromorphine binding studies performed on whole brain synaptic membranes showed a reduction in the maximum number of binding sites in both MS and PS rats; on the other hand, the affinity constant was higher in PS rats, while in MS rats it was similar to that of controls. These data show that the repeated stress of removal from the mother during the first 15 days of life induce a reduction in the number of brain opiate receptors with reduced activity of morphine, while in rats exposed to repeated removal stress associated with painful stimuli the reduction in the number of brain opiate receptors seems to be counterbalanced by their higher affinity.

Animals↗
PubMed1986

Behavioral activity and active avoidance learning and retention in rats neonatally exposed to painful stimuli.

Twice daily for the first 15 days after birth, rats from the same litters were either placed for 5 sec on a hot plate (55 degrees C) (treated group), or on a plate maintained at body temperature (38 degrees C) (manipulated group). Controls were left undisturbed. When 90 days old, they were studied for pain threshold, open-field behavior, and two-way active avoidance learning and retention. Weight gain, pain threshold, open-field behavior, and active avoidance retention were not significantly different in the three groups. On the other hand, the rate of two-way active avoidance learning was significantly greater in treated rats. These results suggest that repeated neonatal exposure to painful stimuli, in rats raised under otherwise normal conditions, improves later active avoidance performance. The most likely mechanisms are discussed.

Acoustic Stimulation↗
PubMed1986

Influence of vagotomy and of atropine on the anti-shock effect of adrenocorticotropin.

ACTH-(1-24), intravenously injected at the dose of 160 micrograms/kg to rats bled to the point of otherwise irreversible hypovolemic shock, causes a prompt and sustained increase in blood pressure and pulse amplitude, all treated rats surviving at the end of the experiment (2 hr). Bilateral vagotomy, as well as atropine sulphate (2 mg/kg i.p. immediately before bleeding), almost completely abolishes the anti-shock activity of ACTH. These data indicate that a central cholinergic pathway and vagal afferent (but not efferent) fibers play an important role in the anti-shock effect of ACTH.

Adrenocorticotropic Hormone↗
PubMed1986

Caerulein and cholecystokinin reverse experimental hemorrhagic shock.

Intravenously injected cholecystokinin octapeptide (CCK-8) (5-20/micrograms/kg) and caerulein (1.25-10/micrograms/kg) caused a prompt, dose-dependent and sustained improvement in blood pressure, pulse amplitude and survival in rats subjected to otherwise invariably fatal hemorrhagic shock.

Animals↗
PubMed1986

Sodium deprivation increases the antinociceptive activity of morphine.

In rats maintained for 50 days on a low-sodium diet and with a compensatory hyperactivity of the renin-angiotensin system, the antinociceptive activity of morphine was significantly longer-lasting than in controls. It is suggested that the renin-angiotensin system modulates opioid system responsivity.

Analgesics↗