Biomedical subjects

A Bertolini

Publications and source records attributed to A Bertolini.

At least 109 records · Page 6Linked to original sources

PubMed1995

Evidence for a role for the neurosteroid allopregnanolone in the modulation of reproductive function in female rats.

The present study investigated the effect of allopregnanolone (5 alpha-pregnan-3 alpha-ol-20-one) or of passive immunoneutralization of brain allopregnanolone, the most potent steroid produced by neurons, on ovulation rate and sexual behavior in female rats. Allopregnanolone was injected intracerebroventricularly in rats on diestrus and proestrus and tests were done on estrus. The intracerebroventricular injection of allopregnanolone significantly decreased the number of oocytes collected on estrus (p < 0.01). To support a physiological involvement, antiserum to allopregnanolone was injected centrally to block the activity of the endogenous neurosteroid. When administered on diestrus and proestrus or only on proestrus, the antiserum was shown to be correlated with a significant increase (p < 0.01) in oocytes retrieved on estrus. In female rats treated with antiserum to allopregnanolone, the lordosis intensity was augmented significantly as compared to controls. Finally, the possible changes of medial basal hypothalamus concentration of allopregnanolone throughout the estrous cycle and at the time of ovulation were investigated. Hypothalamic extracts were eluted on high-pressure liquid chromatography and allopregnanolone concentration was measured by radioimmunoassay. Brain cortex was used as control tissue. Hypothalamic allopregnanolone concentration on proestrus morning and afternoon was found to be significantly lower than in the remaining phases of the estrous cycle (p < 0.01), while no significant changes were observed in brain cortex concentration of allopregnanolone. The present results suggest that hypothalamic allopregnanolone may be involved in the mechanism of ovulation, affecting hormonal and behavioral events.

Animals↗

PubMed1995

Recombinant interferon-alfa therapy in children with chronic hepatitis C.

The efficacy of recombinant interferon-alfa therapy in children with chronic hepatitis C has been evaluated in a randomized, controlled pilot study including 27 patients, aged 2 to 14 years, without underlying systemic diseases. On entry, all patients had abnormal alanine transaminase (ALT) levels, 22 were hepatitis C virus (HCV) RNA positive, 19 had mild chronic active hepatitis, and 8 had chronic persistent hepatitis on liver biopsy. Fourteen children received 5 MU/m2 of recombinant interferon-alfa2b thrice weekly for 4 months. If at this time ALT had been reduced to at least 50% the baseline level, treatment was continued up to 12 months. The other 13 children remained untreated. The whole follow-up period lasted 24 months. Interferon was stopped at 4 months in 4 children because of an ALT increase (2 cases), unchanged ALT and febrile convulsions (1 case), and slight ALT decrease (1 case). This latter patient, however, had normal ALT at 6 months and throughout further follow-up, and cleared HCV RNA, thus behaving as a sustained responder. All 10 children treated for 12 months had normal levels of ALT, and 9 were HCV RNA negative at the end of treatment. Of the 9 children who could be followed to 24 months, 4 relapsed soon after therapy withdrawal and 5 maintained a sustained biochemical and virologic response. Overall, 6 (43%) of 14 treated children had a sustained ALT normalization associated with HCV RNA clearance as compared with only 1 (7.5%) untreated child who had a sustained ALT normalization but did not clear HCV RNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Old rats are unresponsive to the behavioral effects of adrenocorticotropin.

In 28 month-old male rats, the i.c.v. injection of adrenocorticotropin [ACTH-(1-24)] (4 micrograms/rat) did not induce the typical behavioral syndrome (excessive grooming, stretching, yawning, penile erections). This indicates that the behavioral effects of melanocortins are age-dependent, suggesting either an aging-linked impairment of the nervous circuitries involved or a reduction of the number (or affinity, or both) of the brain melanocortin receptors in the elderly.

Aging↗

PubMed1994

Galantide stimulates sexual behaviour in male rats.

While intracerebroventricular injection of galanin (5 micrograms/rat) inhibited sexual behavior in experienced male rats--without producing any other locomotor or behavioral deficit-, injection of the galanin antagonist, galantide, by the same route (1 or 2 micrograms/rat) stimulated sexual behavior (improving arousal, motivation and performance indexes) and antagonized the effect of galanin. These data further suggest that galanin plays a physiological role in male sexual behavior.

Animals↗

PubMed1994

Dopamine D1 receptors are involved in the ACTH-induced reversal of hemorrhagic shock.

In an experimental model of volume-controlled hemorrhagic shock causing the death of all rats within 30 min, the intravenous (i.v.) bolus injection of the adrenocorticotropic hormone fragment 1-24 (ACTH-(1-24)) (160 micrograms/kg) induced a prompt and sustained improvement of cardiovascular and respiratory function, with 100% survival 2 h after treatment. Pretreatment with either haloperidol, 300 micrograms/kg i.v. (antagonist at dopamine D1 and D2 receptors), or (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3- benzazepin-7-ol hemimaleate (SCH 23390), 50 micrograms/kg intraperitoneally (selective antagonist at dopamine D1 receptors), significantly inhibited the effect of ACTH-(1-24). A complete inhibition was produced by intracerebroventricular pretreatment with SCH 23390 (0.1 micrograms/rat). On the other hand, both i.v. and i.c.v. pretreatment with l-sulpiride (selective antagonist at dopamine D2 receptors) (25 mg/kg and 80 micrograms/rat, respectively) had only minor effects. These data suggest that the mechanism of the ACTH-induced reversal of hemorrhagic shock involves the activation of dopamine D1 receptors in the brain.

Analysis of Variance↗

PubMed1994

Influence of ifenprodil on the ACTH-induced behavioral syndrome in rats.

Ifenprodil--an antagonist at the modulatory site of the NMDA receptor complex sensitive to polyamines--intraperitoneally injected at doses of 3 or 10 mg/kg, dose dependently prevented the behavioral syndrome induced by intracerebroventricular administration of adrenocorticotropin (ACTH)-(1-24) in adult male rats (excessive grooming, stretching, yawning, penile erections). These data further support a role of the brain ornithine decarboxylase (ODC)-polyamine system in the ACTH-induced behavioral syndrome, and may suggest an involvement of excitatory amino acids.

Adrenocorticotropic Hormone↗

PubMed1994

Oxytocin enhances, and oxytocin antagonism decreases, sexual receptivity in intact female rats.

In intact, non-ovariectomized female rats in spontaneous behavioral estrus, the i.c.v. injection of oxytocin significantly increased lordosis quotient and lordosis duration, starting from a dose of 1 ng/rat. On the other hand, the oxytocin antagonist, d(CH2)5Tyr(Me)-[Orn]8-vasotocin, injected at the same doses and by the same route, decreased lordosis quotient and lordosis duration, and prevented the effect of oxytocin. These data further support the notion that oxytocin plays a physiological role in female sexual receptivity.

Animals↗

PubMed1994

Benextramine, an NPY antagonist, improves sexual behavior in male rats.

In adult, sexually-experienced male rats, the NPY-antagonist benextramine--at the doses of 5 and 10 mg/kg i.p. and of 50 micrograms/rat i.c.v.--significantly and specifically improved several parameters of copulatory activity. These data may further support the idea that NPY plays a role in the complex regulation of male sexual function, seemingly at the brain level.

Animals↗

PubMed1994

Ability of a new infant formula prepared from partially hydrolyzed bovine whey to induce anaphylactic sensitization: evaluation in a guinea pig model.

In the present study we evaluated the allergenicity and immunogenicity of a whey partially hydrolysate formula (PHF) in a guinea pig model. Nine groups of 10 guinea pigs received either a conventional milk formula (CMF) or PHF for 37 days. After intravenous (i.v.) challenge with either beta-lactoglobulin (beta-L) or ultracentrifuged (u)CMF, animals fed CMF showed, respectively, 80% and 100% fatal reactions, whereas animals fed PHF showed no reactions when i.v. challenged both with beta-L and uPHF. Eighty percent fatal reactions, and 10%, respectively, of severe and mild reactions have been observed in the CMF-fed, casein-challenge group. In contrast, only one (10%) mild reaction occurred in the PHF-fed, casein-challenged group. When challenged with u-pasteurized cow's milk (uPCM), CMF-fed animals showed 86% fatal reactions and 14% mild reactions, whereas PHF-fed ones presented 70% no reactions, 20% mild reactions, and one (10%) fatal reaction. Animals fed CMF showed a significantly higher level of specific IgG against cow's milk antigens than PHF-fed ones, which, however, presented higher levels of antibodies than a water-supplemented control group. The present results confirm that PHF is less sensitizing than CMF in a guinea pig model.

Anaphylaxis↗

PubMed1994

[Endogenous anti-analgesic systems].

Nociception is of vital importance for the organism, while its inhibition by endogenous opioid systems is usually a sign of surrender. Therefore, it must be assumed that endogenous analgesic systems are balanced, and in fact, under normal conditions, overwhelmed, by teleologically far more important anti-analgesic systems. The two main anti-analgesic systems--i.e., the melanotropinergic and the cholecystokininergic--are here reviewed for their role, not only in nociception, but in a wide variety of vital functions (endocrine, gastrointestinal, ingestive, reproductive, cardiovascular, immune, etc.). Available data strongly suggest that these systems (particularly the melanotropinergic one) play a key role in the overall homeostasis of the body. Moreover, modulation of endogenous anti-analgesic systems may disclose a new, unforeseen approach to the treatment of pain.

Analgesia↗

PubMed1994

Aortopulmonary septal defects. A review of the literature and report of ten cases.

From 1981 to 1992, 10 infants with aortopulmonary septal defect (APSD) underwent surgical repair. The mean age at operation was 5.6 +/- 5.5 months, and the mean weight 4.6 +/- 2 kg. Intracardiac associated anomalies were as follows: ventricular septal defects (7 cases), tetralogy of Fallot (2 cases), aortic valve stenosis (2 cases), atrial septal defect (3 cases), patent ductus arteriosus (3 cases), pulmonary valve stenosis (1 case). Cardiac catheterization was performed in 8 out of 10 patients. Eight patients had type I (proximal) defect, 1 had type II (distal) defect and 1 had type III (absent aortopulmonary septation) defect. A variety of surgical procedure was employed. APSD closure with hemoclip was feasible in 3 cases with small window. In 6 patients, during a period of cardiopulmonary by-pass, a side biting clamp was positioned on the ascending aorta close the defect; the border of the window was divided leaving a flap of pulmonary wall on the left side to close the aortic defect; the pulmonary artery was repaired by an autologous pericardial patch. In the patient with type III APSD, aortopulmonary septation was carried out through a transwindow approach. Associated anomalies were repaired in all infants except one. Hospital mortality was 10% (1 case). No late deaths occurred. At a mean follow-up of 47 +/- 35 months 8 patients are asymptomatic and 1 is awaiting for repair of associated anomalies. Conclusions. APSD is a rare but nonetheless well identifiable anomaly. Surgery is indicated as soon as the diagnosis is established, regardless of the patient's age.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1993

The effect of oxytocin on feeding, drinking, and male copulatory behavior is not diminished by neonatal monosodium glutamate.

The effect of oxytocin on feeding, drinking, and male copulatory behavior was studied in rats neonatally injected with monosodium glutamate (MSG), a treatment that destroys neuronal perikarya of the arcuate nucleus and depletes the brain of proopiomelanocortin-derived peptides (melanocortins, endorphins). Both oxytocin-induced inhibition of feeding (1 and 10 micrograms/rat ICV and 150 micrograms/rat IP) and drinking (75 and 150 micrograms/rat IP) and oxytocin-induced improvement of male copulatory behavior (200 ng/rat IP) were either unaffected or in fact increased by neonatal MSG treatment. These data suggest that oxytocin neither inhibits feeding and drinking nor improves male sexual behavior through the release of melanocortin peptide(s) in the brain.

Animals↗

PubMed1993

The behavioral syndrome induced by adreno corticotropic hormone in rats is prevented by Ca++ channel blockade.

The most typical signs (stretchings, yawnings, penile erections, excessive grooming) of the behavioral syndrome induced in rats by the intracerebroventricular administration of ACTH- (1-24) (4 micrograms/rat) were dose-dependently antagonized by the intraperitoneal injection of the selective Ca++ channel inhibitor, nicardipine (dose range: 0.1-1 mg/kg). These data suggest that the influx of Ca++ into target neurons is a step of key importance for the occurrence of ACTH-induced behavioral signs, and that Ca++ may play the role of second intracellular messenger for the behavioral effects of melanocortins.

Animals↗

PubMed1993

Lack of influence of aromatase and 5 alpha-reductase inhibition on [3H]imipramine binding in the male rat brain.

In intact adult male rats an inhibitor of aromatase and an inhibitor of 5 alpha-reductase did not change the characteristics of [3H]imipramine binding sites in cerebral cortex, hypothalamus, and hippocampus. Testosterone, estradiol and dihydrotestosterone prevented the effect of castration on the number of [3H]imipramine binding sites, but had no effect in non-castrated animals. These data suggest that testosterone and its major metabolites, estradiol and dihydrotestosterone, are equally effective with regard to imipramine binding sites.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed1993

Influence of oxytocin on nociception and morphine antinociception.

In the hot plate test the intracerebroventricular (i.c.v.) injection of oxytocin produced a significant decrease in nociception, starting from the dose of 1 microgram/rat. A comparable effect was obtained with 10-200 times higher intraperitoneal (i.p.) doses. The i.c.v. injection of the oxytocin antagonist d(CH2)5-Tyr(Me)-[Orn8]-vasotocin, while having no influence per se, completely prevented the antinociceptive effect of an equal i.c.v. dose of oxytocin. The antinociceptive effect of oxytocin was also prevented by naltrexone, and oxytocin caused a small but significant increase of the antinociceptive effect of morphine and of its duration. These data indicate that pharmacological amounts of oxytocin produce antinociception, that occurs through the activation of oxytocin receptors; endogenous opioid systems seem to be involved altogether.

Animals↗

PubMed1993

Comparison of the effects of ACTH-(1-24), methylprednisolone, aprotinin, and norepinephrine in a model of hemorrhagic shock in rats.

Rats bled to a severe condition of volume-controlled hemorrhagic shock were randomly assigned to one of the following treatments: (1) saline, 1 ml/kg i.v.; (2) saline, 0.2 ml/kg per min i.v. for 10 min; (3) ACTH-(1-24), 160 micrograms/kg i.v.; 4) methylprednisolone, 40 mg/kg i.v.; (5) methylprednisolone, 80 mg/kg i.v.; (6) aprotinin, 10,000 KIU/kg i.v.; (7) norepinephrine, 5 micrograms/kg per min i.v. for 10 min; (8) norepinephrine, 10 micrograms/kg per min i.v. for 10 min. All rats treated with saline or with either of the two doses of methylprednisolone, and half of the rats treated with aprotinin, died within the subsequent 2 h. On the other hand, rats treated with norepinephrine, at either dose, or with ACTH-(1-24) were all still alive 2 h later, a similar improvement in cardiovascular and respiratory parameters being obtained with the two treatments. The effect of ACTH on mean arterial pressure was however more sustained throughout the observation period. These results further support the potential usefulness of ACTH-(1-24) as first-aid treatment in cases of severe blood losses.

Animals↗

PubMed1993

Selection of a precore mutant of hepatitis B virus and reactivation of chronic hepatitis B acquired in childhood.

A 14-year-old girl with chronic hepatitis B had seroconversion from hepatitis B e antigen to antibody and achieved biochemical remission after 2 years. The disease reactivated 9 years later when a precore mutant had become the prevalent hepatitis B virus strain in serum. These results suggest that selection of a precore mutant might induce reactivation during adult life of chronic hepatitis B acquired in childhood, thus worsening the prognosis.

Adolescent↗

PubMed1993

NGF is released into plasma during human pregnancy: an oxytocin-mediated response?

The presence of biologically active nerve growth factor (NGF) in the peripheral circulation of women during pregnancy, labour and lactation was investigated. Using a sensitive immunoenzymatic assay (ELISA), we found an approximately five-fold increase in plasma NGF levels during labour and lactation compared with the concentrations found at the term of gestation or in control healthy women. Since labour and lactation are characterized by activation of the hypothalamo-pituitary-adrenal axis and by high plasma levels of the neurohypophyseal hormone oxytocin, and since the intravenous injection of oxytocin in female rats causes a 176% increase in the hypothalamic levels of NGF, it is possible that the increased amount of circulating NGF is correlated with one or both of these events.

Adolescent↗