Search PubMed⌕ Search

Biomedical subjects

F Drago

Publications and source records attributed to F Drago.

At least 37 records · Page 2Linked to original sources
PubMed2001

Radiofrequency catheter ablation of idiopathic left ventricular outflow tract tachycardia: utility of intracardiac echocardiography.

INTRODUCTION: The site of origin of idiopathic ventricular tachycardia (VT) arising from the left ventricular outflow tract (LVOT) may be closely related to the aortic valve leaflets, and radiofrequency (RF) delivery potentially can damage them. Intracardiac echocardiography (ICE) can identify accurately the ablation electrode and anatomic landmarks, and contact with the endocardium can be easily assessed. The aim of this study was to define the utility and the accuracy of ICE in guiding RF ablation of idiopathic VT of the LVOT. METHODS AND RESULTS: Five consecutive patients (all men; mean age 20.4 years, range 16 to 25) symptomatic for idiopathic VT underwent RF ablation. A 9-French, in-sheath catheter with a 9-MHz ultrasound transducer was inserted through the femoral vein and positioned in the His-bundle region or right ventricular outflow tract to provide a clear view of the aortic root. Local earliest ventricular activation during tachycardia and pace mapping were used to identify the ablation site. Idiopathic VT was ablated successfully in all patients using a median of two RF pulses, delivered during tachycardia. High-resolution images of the aortic valve and ablation electrode were achievable in all cases. Direct vision of ablation electrode-endocardial contact in the outflow tract was assessed easily in all patients. CONCLUSION: Idiopathic VT of the LVOT can be treated successfully with RF ablation. ICE can accurately guide catheter ablation and identify anatomic landmarks, endocardial contact, and ablation electrode movement.

Adolescent↗
PubMed2001

Amiodarone-induced torsade de pointes in a child with dilated cardiomyopathy.

Amiodarone has a high incidence of side effects, but few pro-arrhythmic effects. We report a case of amiodarone-induced torsade de pointes in a child aged 10 years. The patient had severe dilated cardiomyopathy, and even though he was treated with low oral doses of amiodarone, without dosage increments and electrolyte imbalance, he developed torsade de pointes at nights, after T-wave modification and increases of the corrected QT interval (QTc, 20%), QT dispersion (QTd, 175%) and QTcd (116%). The arrhythmic events were preceded by sinus bradycardia at Holter monitoring. Amiodarone therapy was discontinued. Intravenous magnesium administration was not effective in the suppression of torsade de pointes. High-rate atrial pacing prevented recurrences of the arrhythmias and reduced the QTc interval by 20%, QTd by 50%, and QTcd by 70%; QTd and QTcd returned below normal limits. This case underscores the need of careful electrocardiographic monitoring during amiodarone therapy.

Administration, Oral↗
PubMed2001

Permanent junctional reciprocating tachycardia in infants and children: effectiveness of medical and non-medical treatment.

BACKGROUND: The aim of this study was to identify, in children affected by permanent junctional reciprocating tachycardia (PJRT), the effective treatment. METHODS: Seventeen children (9 males, 8 females, mean age 59 +/- 62 months, median 24) affected by PJRT were referred to our Institute between the years 1987 and 2000. RESULTS: Pharmacological therapy was successfully used in 14 patients: flecainide and propranolol in 5 of them, amiodarone alone in 5 and associated with propranolol in 2, propafenone alone in 1 and in association with sotalol in 1. These drugs were given for a mean period of 54.5 +/- 49.8 months with resolution of the cardiomyopathy in 7/7 patients. Treatment had been continued for 3-6 months and there were no side effects. Nine patients were treated with radiofrequency transcatheter ablation, after 78 +/- 53.5 months of medical treatment, at a mean age of 150 +/- 16 months. The shortest endocardial ventriculo-atrial (VA) interval during tachycardia was recorded in all cases at the coronary sinus ostium (mean value of local VA-surface RP' interval -38 ms, range -24/-55 ms). Successful ablation of the anomalous pathway was obtained at this site in all patients (mean watts delivered 26 +/- 3 W, mean T degrees 64 +/- 5 degrees C). During the follow-up period (mean 21 +/- 17 months) 2 patients with recurrences of PJRT underwent a second successful procedure. CONCLUSIONS: PJRT in pediatric patients can be successfully treated with antiarrhythmic drugs, this may allow delay of the highly effective radiofrequency ablation treatment until the children have reached an adequate growth.

Adolescent↗
PubMed2000

Acute low doses of melatonin restore full sexual activity in impotent male rats.

Evidence exists that repeated injections of melatonin in rather large doses inhibit sexual performance in male rats. In contrast, systemic injection of small doses of this hormone stimulates sexual activity of normal male rats. In these experiments, systemic acute administration of melatonin in small doses (10-100 microg/kg) induced the appearance of ejaculations in impotent Wistar male rats that were selected as showing null sexual approach or showing mounts, intromissions but no ejaculations. This effect was partially abolished by the simultaneous peripheral injection of the non-selective melatonin receptor antagonist, luzindole, or by the acute administration of serotonin or of the 5HT(2A) receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), into the amygdala or the ventral hypothalamus. These results suggest that melatonin may stimulate, in a dose-dependent manner, several copulatory parameters of male sexual behavior and may restore sexual activity in impotent animals by interacting with brain receptors, i. e. melatonin and serotonin receptors.

Amphetamines↗
PubMed2000

The "low-dose" concept and the paradoxical effects of prolactin on grooming and sexual behavior.

The effects of prolactin on animal behavior include the stimulation of novelty-induced grooming in rats. This effect has been demonstrated in hyperprolactinaemic animals bearing pituitary homografts under the kidney capsule or after intracerebroventricular (i.c.v.) administration of prolactin. Since plasma prolactin levels in hyperprolactinaemic rats are similar to those of animals injected with low doses of rat prolactin, we studied the effects of this hormone injected subcutaneously (s.c.) in a dose range of 5-50 microg/kg. Novelty-induced grooming was enhanced only in rats injected with 5 or 10 microg/kg rat prolactin, whereas no effect was observed after the s.c. injection of the higher dose. The sexual behavior of male rats is also affected by prolactin. Male rats with normal mating activity showed enhanced sexual behavior when injected s.c. with rat prolactin (5, 10 or 50 microg/kg). In animals with poor sexual performance or in impotent rats, prolactin (5 or 10 microg/kg, but not 50 microg/kg) restored the full pattern of sexual behavior. An increased lordosis quotient was also observed in ovariectomized rats treated with prolactin 5 or 10 microg/kg. These results suggest that, besides the duration of hyperprolactinaemia, the effective level of plasma prolactin is important for the expression of the behavioral effects of this hormone.

Animals↗
PubMed2000

Adrenomedullin and ocular inflammation in the rabbit.

Adrenomedullin administered peripherally in the rabbit (at doses of 1.25, 2.5 and 5 microg/kg ) caused a dose-dependent conjunctival hyperemia accompanied by an increase of inflammatory cell number and prostaglandin E(2) concentration in the aqueous humor, and of uveal vascular response and myeloperoxidase activity. The inflammatory effect of the peptide, injected at the dose of 5 microg/kg, was abolished by pretreatment with the inhibitor of nitric oxide synthase, N(G)-nitro-L-arginine methylester (50 mg/kg, i.v.). Moreover, the i.v. pretreatment with the calcitonin gene-related peptide 8-37 fragment (calcitonin gene-related peptide, CGRP-(8-37), 2.5 microg/kg), receptor antagonist of CGRP, did not inhibit the conjunctival hyperemia. In contrast, the i.v. pretreatment with the adrenomedullin receptor antagonist, adrenomedullin-(22-52) fragment (2.5 microg/kg), abolished adrenomedullin-induced ocular inflammation. These results suggest that adrenomedullin causes conjunctival hyperemia, and this effect involves the nitric oxide system acting through specific adrenomedullin receptors.

Adrenomedullin↗
PubMed2000

Effects of acute or chronic administration of substituted benzamides in experimental models of depression in rats.

The effects of substituted benzamides, sulpiride and raclopride on experimental models of depression were studied in male rats after acute or chronic administration in comparison to those of the classical antidepressant, clomipramine. In contrast to clomipramine (50 mg/kg), acute doses of sulpiride or raclopride (1 or 5 mg/kg) failed to change the behavioral response of animals tested in the despair (constrained swim) test or in the model of reserpine-induced changes in the open field behavior. These doses also did not modify the grooming response of rats exposed to a novel environment. Sulpiride or raclopride 10 mg/kg increased the immobility time in the despair test and reduced novelty-induced grooming. The repeated injection for 21 days of sulpiride or raclopride (1 or 5 mg/kg, but not 10 mg/kg) induced a reduction of the immobility period during the constrained swim test similar to that following the chronic treatment with clomipramine 50 mg/kg. This appeared to be a clear-cut reversed dose-response relationship for both substituted benzamides, being the dose potency 1 mg/kg>5 mg/kg>10 mg/kg. Raclopride was more potent than sulpiride in this respect. Furthermore, like clomipramine, sulpiride (1 or 5 mg/kg) and raclopride (1 mg/kg) antagonized reserpine-induced changes in the open field behavior and enhanced novelty-induced grooming. These results indicate that, in contrast to acute injection, repeated administration of small doses of the substituted benzamides, sulpiride or raclopride induce an effect similar to that of the classical antidepressant, clomipramine. The reverse dose-response relationship suggests that these drugs in small doses act on presynaptic dopamine D(2) receptors. This may be consistent with a postsynaptic action of greater doses that exert sedative effects and increase immobility time in the despair test.

Animals↗
PubMed2000

Cytomegalovirus infection in normal and immunocompromised humans. A review.

Although cytomegalovirus (CMV) disease is a severe complication among immunocompromised patients, its cutaneous features have not been reported frequently. CMV belongs to the Herpesviridae family sharing with the other members the ability to remain latent in their natural hosts after an initial infection and to produce overt disease in several settings. The natural history of human CMV infection is characterized by primary infection, latent infection and reinfection. This article reviews the extremely variable aspects of the clinical presentation of CMV infection in normal and immunocompromised humans, focusing on the dermatological manifestations, and indicates the laboratory tests for detecting CMV responsibility in skin disorders.

Cytomegalovirus Infections↗
PubMed1999

Acute low doses of melatonin stimulate rat sex behavior: the role of serotonin neurotransmission.

Melatonin is known to inhibit male and female sex behavior, but this effect has been reported only after repeated administration of sustained doses of the hormone. The present experiments were performed in order to study the effects of acute treatment with low doses of melatonin on rat male and female sex behavior in a dose-response paradigm. After four mating tests with a receptive female, sexually active male rats of the Wistar strain were injected intraperitoneally (i.p.) with small doses of melatonin (10, 50 and 100 microg/kg) administered acutely 1 h before a 30-min mating test. Melatonin (50 and 100 ng/2 microl) or its analogs, 6-chloromelatonin (2 and 4 ng/2 microl) and 2-iodomelatonin (5 and 10 ng/2 microl) were also injected intracerebroventricularly (i.c.v.) 30 min before mating. Either treatments caused a reduction of the latency to the first mount, intromission and ejaculation. An increase in the frequency of mounts, intromissions and ejaculations was also observed. Inhibition of sexual activity was observed when a greater dose (1 mg/kg) of melatonin was repeatedly injected for 14 days. Female sex behavior, measured by the lordosis quotient in Wistar female rats, was not affected by acute treatment with the hormone, while it appeared to be inhibited by the repeated injection. The facilitating effect of acute i.p. or i.c.v. melatonin low doses on sexual activity of male rats was partially abolished by the pre-treatment with the non-selective melatonin antagonist, luzindole (0.25 mg/kg, injected subcutaneously), and totally suppressed by the injection of small quantities of serotonin or the 5H(2A)-5H(2C) receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane into the amygdala. These results suggest that melatonin may exert opposite effects on male and female sex behavior depending on the dose and duration of treatment.

Amphetamines↗
PubMed1999

Nicergoline facilitates vestibular compensation in aged male rats with unilateral labyrinthectomy.

The ergoline derivatives, nicergoline (NIC) or dihydroergocristine (DHE) were administered at various doses (0.1, 0.5 and 1 mg/kg) to aged male rats subjected to labyrinth unilateral lesion (LBX). The nystagmus rate appeared to be lower in animals treated with DHE or NIC 1mg/kg than in saline-injected rats, when observed on day 1 and 2 after operation. The number of falls in the rotorod test of LBX animals was decreased by NIC 0.5 or 1 mg/kg at all observation times. This parameter was affected by DHE only at the higher dose. These results suggest that NIC facilitates vestibular compensation of LBX rats. DHE appeared to be less potent in this respect. Since both drugs act on central dopaminergic neurotransmission, it is possible that this neurotransmission may be involved in their mechanism of action.

Age Factors↗
PubMed1999

A new place conditioning paradigm to study tolerance to opiates in mice.

Tolerance to the rewarding properties of morphine was investigated in mice using a new conditioned place preference (CPP) procedure. Four pairings of morphine with specific environmental cues induced a significant CPP for the drug-paired cues. Further opiate conditioning trials in the presence of the same environmental cues revealed no change in the drug-induced CPP on repeated test sessions. Subsequent exposure of the same animals to conditioning trials by pairing morphine with a set of novel environmental cues showed that the opiate was still able to produce a CPP in mice treated with a total of 16 morphine injections. The present CPP paradigm may prove useful to investigate tolerance to the rewarding properties of drugs of abuse.

Animals↗
PubMed1999

The expression of neuropeptide-induced excessive grooming behavior in dopamine D1 and D2 receptor-deficient mice.

Grooming behavior in rodents has long been related to dopamine receptors in the brain. However, the relative contribution of dopamine D1-like receptors (D1 and D5) and D2-like receptors (D2, D3 and D4) in this behavior has not been established yet. Spontaneous novelty-induced grooming (as assessed with a 30-min sampling test) was reduced in knockout mice lacking the dopamine D1, receptor. Furthermore, the intracerebroventricular (i.c.v.) injection of small quantities of oxytocin, prolactin or the adrenocorticotrophic hormone 1-24 fragment, ACTH-(1-24) was followed by a diminished level of novelty-induced excessive grooming. These neuropeptides caused a sustained increase in grooming level of control animals (wild type). Interestingly, the i.c.v. injection of beta-endorphin enhanced novelty-induced grooming to a level similar in control and knockout mice. The systemic administration of the dopamine D2 receptor antagonist, sulpiride did not suppress the residual grooming activity shown by animals injected with oxytocin, prolactin or ACTH-(1-24), and did not change the behavioral expression of those injected with beta-endorphin. In contrast, the systemic administration of the opioid receptor antagonist, naloxone, totally suppressed the residual grooming activity of oxytocin-, prolactin- or ACTH-(1-24)-injected mice and of those treated with beta-endorphin. In contrast with the behavioral deficit observed in dopamine D1 receptor-deficient mice, dopamine D2 receptor-null animals showed a normal expression of spontaneous novelty-induced grooming and a high level of grooming activity induced by i.c.v. injection of oxytocin, prolactin, ACTH-(1-24) or beta-endorphin. Again, the peripheral injection of naloxone was followed by a suppression of neuropeptide-induced excessive grooming in these animals. These data suggest that dopamine D1 receptors are involved in the expression of novelty-induced grooming in mice. In contrast, dopamine D2 receptors seem not to be important for the expression of this behavior. Furthermore, neuropeptide-enhanced grooming involves dopamine D1, but not dopamine D2 receptors. However, neurotransmitters other than dopamine (e.g., endorphins) may play a supplementary role in neuropeptide-enhanced grooming in mice.

Animals↗
PubMed1999

The new herpesviruses: emerging pathogens of dermatological interest.

OBJECTIVES: To discuss the current knowledge of 3 recently discovered human herpesviruses (HHV-6, HHV-7, and HHV-8), and to provide a dermatological point of view. DATA SOURCES: References identified from bibliographies of pertinent articles in the English language. STUDY SELECTION AND DATA EXTRACTION: Articles were selected according to their impact factor and the interest for dermatologists. DATA SYNTHESIS: As the other members of the family Herpesviridae, HHV-6, HHV-7, and HHV-8 may cause a primary infection, establish latent infection in a specific set of cells of their host, and then reactivate if conditions of altered immunity develop. The main pathological conditions associated with them are discussed. CONCLUSIONS: Human herpesvirus 6, HHV-7, and HHV-8 have provided new insights in some dermatological diseases. Although new studies are needed, they may have a profound impact on dermatology in the years to come.

Exanthema Subitum↗