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Biomedical subjects

F Drago

Publications and source records attributed to F Drago.

At least 19 recordsLinked to original sources
PubMed2006

Endocannabinoids and beta-amyloid-induced neurotoxicity in vivo: effect of pharmacological elevation of endocannabinoid levels.

We investigated the involvement of endocannabinoids in the control of neuronal damage and memory retention loss in rodents treated with the beta-amyloid peptide (1-42) (BAP). Twelve days after stereotaxic injection of BAP into the rat cortex, and concomitant with the appearance in the hippocampus of markers of neuronal damage, 2-arachidonoyl glycerol, but not anandamide, levels were enhanced in the hippocampus. VDM-11 (5 mg/kg, i.p.), an inhibitor of endocannabinoid cellular reuptake, significantly enhanced rat hippocampal and mouse brain endocannabinoid levels when administered sub-chronically starting either 3 or 7 days after BAP injection and until the 12-14th day. VDM-11 concomitantly reversed hippocampal damage in rats, and loss of memory retention in the passive avoidance test in mice, but only when administered from the 3rd day after BAP injection. We suggest that early, as opposed to late, pharmacological enhancement of brain endocannabinoid levels might protect against beta-amyloid neurotoxicity and its consequences.

Amyloid beta-Peptides↗
PubMed2006

A distinctive erythematous macular exanthem of the adult: a new entity?

BACKGROUND: Delineating a new exanthem is difficult. Atypical or modified types of already known conditions can easily be mistaken for new entities. OBJECTIVES: To report 29 cases of an acute, self-limiting exanthem never described before. METHODS: Clinical description, serology, polymerase chain reaction (PCR) and other laboratory investigations. RESULTS: The eruption starts with bright pink-red slightly oedematous macules symmetrically arranged on the trunk. The lesions tend to coalesce, and spread to the limbs on which they may acquire a marginated annular appearance. The lesions invariably spare the face (including oral mucous membranes), palms and soles. The eruption is pruritic and lasts 20-30 days, clearing spontaneously. The disease has a predilection for men aged 17-56 years and occurs mostly between spring and summer. Serological tests, PCR assays and investigations for bacteria, parasites or viruses were consistently negative. CONCLUSIONS: The clinical picture does not recall any of the classical exanthems or their atypical forms.

Acute Disease↗
PubMed2005

Dopaminergic drugs may counteract behavioral and biochemical changes induced by models of brain injury.

The dopaminergic drugs, bromocriptine, cabergoline, dihydroergocryptine, pergolide and ropinirole were injected subcutaneously (s.c.) at the dose of 0.1, 0.5 and 1 mg/kg/day for 7 days into male rats of the Sprague-Dawley strain. The drug pre-treatment reverted amnesia induced in rats by hypobaric hypopxia and tested in active and passive avoidance tasks. A restoration of memory retention, as assessed in a step-through passive avoidance task, was found in animals with a 2-month brain occlusive ischemia and exposed to dopaminergic drugs for 7 days. For behavioral effects in both active and passive avoidance tests in both experimental models, the rank of relative potency was ropirinole>bromocriptine=cabergoline>pergolide>dihydroergocryptine. Spontaneous ambulation of animals with brain occlusive ischemia was increased by the higher doses of drugs. All dopaminergic drugs reduced kainate mortality rate. The rank of relative potency for this effect was ropirinole=bromocriptine=cabergoline>pergolide=dihydroergocryptine. However, no change was found in other seizure parameters (latency to first convulsion and total number of convulsions) after drug treatment. A biochemical analysis of glutathione redox index (glutathione reduced/glutathione oxidized ratio) in discrete brain areas revealed that exposure to dopaminergic drugs increased this parameter in frontal cortex, striatum and hippocampus of animals subject to hypobaric hypoxia and brain occlusive ischemia. For this effect, the relative potency rank was ropirinole>bromocriptine=cabergoline>>pergolide=dihydroergocryptine. These behavioral and biochemical findings suggest that dopaminergic drugs may counteract either behavioral or biochemical changes induced by experimental models of brain injury. This activity was found after protective activity (as found in animals pre-treated with these drugs and exposed to hypobaric hypoxia) or reversal of brain injury (as found in animals treated after 2-month occlusive brain ischemia). Their neuroprotective activity probably involves the reduction/oxidation balance of the glutathione system in the brain.

Amnesia↗
PubMed2004

Paroxysmal atrioventricular block in young patients.

We describe 17 patients (8 girls, and 9 boys), aged 9.6 +/- 5.7 years, with paroxysmal atrioventricular block (PAVB), a condition rarely described in children. Holter monitoring documented the PAVB in 15 patients, and tilt test was performed in 4 patients (positive in 1). The electrocardiograph (ECG) was normal in 7 patients. Two patients had acquired and 11 patients had congenital heart disease (CHD). Syncope or presyncope were present in 7 patients. A normal ECG was significantly more frequent in symptomatic patients. Pauses were significantly longer in girls and in children <5 years. PAVB was recorded only during nocturnal hours in 6 patients and throughout the day in the others. The sinus rate decreased during PAVB in 6 patients and increased in 4 (generally younger girls with symptoms). Permanent pacemakers were implanted in 13 patients, including 7 asymptomatic patients with CHD and severe bradycardia. During follow-up (3.7 +/- 2.5 years), 1 patient developed complete AVB. Although PAVB was still present in 91% of paced patients, symptoms did not recur because pacing prevented the pauses. In conclusion, PAVB is a rare arrhythmia. Autonomic nervous system dysfunction seems to play an etiological role and permanent pacing was an effective treatment.

Adolescent↗
PubMed2004

Riluzole restores motor activity in rats with post-traumatic peripheral neuropathy.

Riluzole is a presynaptic inhibitor of glutamate release with neuroprotective properties. In order to evaluate the effects of riluzole on motor activity in post-traumatic peripheral neuropathy (PTPN), the sciatic nerve of Wistar male rats was exposed monolaterally and subjected to crushing for one min by a surgical forceps. Animals received an intraperitoneal treatment with riluzole (2, 4 or 8 mg/kg per day), diclofenac (5, 10 or 20 mg/kg) or with vehicle for 3 days. Motor activity and coordination was evaluated in a circular open field and in the rotorod test. The treatment with riluzole stimulated ambulation in PTPN rats and improved their motor performance and coordination. The effect of treatment with riluzole on locomotor activity was greater than that of treatment with diclofenac and was dose-dependent. Furthermore, in contrast to vehicle- and diclofenac-treated rats, animals treated with riluzole showed a long-lasting improvement of locomotor activity as it was assessed 7 days after the end of treatment. These findings suggest that riluzole may improve motor performance in PTPN, and this does not depend on its antinociceptive activity. Its neuroprotective properties are possibly involved in this effect.

Animals↗
PubMed2002

Does chronic pacing affect exercise capacity after Mustard operation for transposition of the great arteries?

Late survival after Mustard repair of transposition of the great arteries is generally good but is often characterized by progressive deterioration of ventricular function and by late postsurgical arrhythmias, thus imposing the need for permanent pacing. To evaluate how chronic pacing affects long-term exercise capacity, we compared two groups of these patients: group 1, comprising 12 patients, aged 9.0 +/- 2.6 years, without pacemaker; and group 2, comprising 18 patients, aged 9.3 +/- 2.0 years, with pacemaker. Patient evaluation included history, physical examination electrocardiograph, Holter monitoring, and echocardiography. Pacing modes were as follows: AAI (6 patients), AAIR (9 patients), VVI (2 patients), and VVIR (1 patient). At exercise test we evaluated exercise tolerance, maximum heart rate, blood pressure, oxygen consumption, and cardiac output at rest and at peak exercise. The two groups were comparable for all variables examinated. All pacemakers showed normal function. During the exercise, 11 of 12 patients in group 1 showed sinus rhythm, and in group 2, 11 patients showed sinus rhythm, 5 junctional rhythm, and 2 continuous pacing. There were no significant differences between groups. Chronically paced Mustard patients but with restoration of spontaneous rhythm during the exercise test do not show reduced exercise tolerance in comparison with nonpaced Mustard patients.

Arrhythmias, Cardiac↗
PubMed2002

Behavioral and neurochemical effects of dopaminergic drugs in models of brain injury.

The dopaminergic drugs, ropinirole and dihydroergocryptine (DHECP) were injected subcutaneously (s.c.) at doses of 0.5 and 1 mg/kg/day for 7 days into male rats of the Sprague-Dawley strain. The drug pretreatment reverted amnesia induced in rats by hypobaric hypopxia and tested in active and passive avoidance tasks. Furthermore, a partial restoration of memory retention was found in animals with a 2-month brain occlusive ischemia induced by manipulation of the four major arteries of the brain. No major changes were found in spontaneous motor activity, but drug treatment increased ambulation of animals subjected to acute or chronic experimental manipulation. In a model of kainate-induced epilepsy, ropinirole or DHECP did not affect seizure parameters, but reduced mortality rate. At the end of behavioral procedures, in all animals subjected to hypobaric hypoxia or to brain occlusive ischemia glutathione redox index (glutathione reduced/glutathione oxidized ratio) was measured in the frontal cortex, striatum and hippocampus. It was found that experimental models of brain injury were followed by a decrease of reduced glutathione content in all brain areas. The glutathione redox index was augmented by ropinirole or DHECP treatment in all brain areas. These behavioral and neurochemical findings suggest that ropinirole and DHECP may exert either protective activity (as found in animals pretreated with these drugs and exposed to hypobaric hypoxia) or reversal of brain injury (as found in animals treated after two-month occlusive brain ischemia). Thus, both drugs may be studied as therapeutic agents in brain injuries of various origin.

Animals↗
PubMed2002

Atypical exanthems: morphology and laboratory investigations may lead to an aetiological diagnosis in about 70% of cases.

BACKGROUND: Besides the six classical exanthems, other exanthems may occur, differing in morphology and causative agent (atypical exanthems). Their aetiological diagnosis is difficult but crucial for both the patient and community concerning issues such as time off school, immunizations, and risks for pregnant women and immunocompromised patients. OBJECTIVES: To investigate whether morphology, associated symptoms and laboratory results can help to determine the aetiology of atypical exanthems. METHODS: We studied 112 consecutive out-patients attending two university dermatology departments. Peripheral blood mononuclear cells (PBMC) and throat, rectal and vaginal swabs were studied to identify viral and bacterial growth. Nested polymerase chain reaction was performed on PBMC and plasma using specific primers for herpesviruses. Serology for common viruses was investigated. RESULTS: We classified the exanthems into seven morphological patterns: macular erythema (32 patients), papular erythema (eight), maculopapular erythema (42), maculopapular erythema with petechiae (seven), erythema with vesiculation (11), erythema with pustules (five) and urticaria (seven). On the basis of morphology, in concert with the associated symptoms and laboratory results, we found a causal relationship in 76 patients (68%): 25 cases due to drugs, 32 to viruses, 16 to bacteria and three to parasites. A good correspondence between morphology and aetiology was found. The erythematous-vesicular pattern was exclusive to viral infections and was often accompanied by enanthema. The erythemato-pustular and papular patterns were found only in drug-related cases and in some undiagnosed cases. In contrast, the macular and maculopapular patterns were almost evenly distributed among the various aetiologies, although their colour was duskier in the drug-related exanthems. Severe pruritus was associated with drug-related exanthems. CONCLUSIONS: This is the largest series of consecutive patients with atypical exanthems reported. Their morphology and their association with pruritus or constitutional symptoms proved to be important diagnostic clues.

Adolescent↗
PubMed2001

Dual effects of melatonin on barbiturate-induced narcosis in rats.

Melatonin affects the circadian sleep/wake cycle, but it is not clear whether it may influence drug-induced narcosis. Sodium thiopenthal was administered intraperitoneally into male rats pre-treated with melatonin (0.05, 0.5, 5 and 50 mg/kg). Melatonin pre-treatment affected in a dual manner barbiturate narcosis, however, no dose-effect correlation was found. In particular, low doses reduced the latency to and prolonged the duration of barbiturate narcosis. In contrast, the highest dose of melatonin (50 mg/kg) caused a paradoxical increase in the latency and produced a sustained reduction of the duration of narcosis, and a reduction in mortality rate. Melatonin 0.5 and 5 mg/kg influenced the duration but not the latency of ketamine- or diazepam-induced narcosis. Thus, the dual action of melatonin on pharmacological narcosis seems to be specific for the barbiturate mechanism of action.

Adjuvants, Anesthesia↗
PubMed2001

Latanoprost exerts neuroprotective activity in vitro and in vivo.

Prostaglandins may influence cyclo-oxygenase (COX-2) and nitric oxide (NO) synthase activity, thus interfering with ischemia-induced neurotoxic processes. The prostaglandin synthetic derivative, latanoprost was tested in different in vivo and in vitro models of neuronal damage in order to study its influence on these processes. Ischemia was induced in rats by bilateral occlusion of the carotid arteries for 30 min. Latanoprost (0.01 mg x kg(-1)per die, i.p. for 3 days) or the ionotropic glutamate receptors antagonist, MK-801 (0.1 mg x kg(-1)per die, i.p. for 3 days) were equal in preventing lactate accumulation in retinal tissue of animals subjected to acute ischemia. Similar results were obtained in animals with retinal ischemia induced by increasing intraocular pressure to 120 mm Hg for 45 min. PGF2alpha, PGE2, latanoprost and acid of latanoprost (PhXA85) reduced the release of LDH from primary cultures of human retinal cells in vitro subjected to glutamate (10 microM) or hypoxia/re-oxygenation exposure. This effect was observed only at concentrations of 1-0.01 microM for PGF2alpha and PGE2, and of 0.1-0.001 microM for latanoprost (0.01 microM-0.1 nM for PhXA85). The COX-2 activity in cultured retinal cells exposed to glutamate was measured as PGE2 production when latanoprost was applied compared to arachidonic acid (AA) at different molar concentrations. The COX-2 activity was reduced by arachidonic acid (0.1-0.01 microM) as well as by latanoprost (0.1-0.001 microM) and PhXA85 (0.01-0.001 microM) in retinal cells exposed to glutamate. Inhibition of inducible NO synthase was also found with the same drug concentrations. These results suggest that latanoprost exerts a neuroprotective activity in vitro and in vivo. This effect seems to be present only at low concentrations of the drug. A negative feedback on neuronal COX-2 activity may be possibly involved.

Analysis of Variance↗
PubMed2001

Heart rate variability in healthy children and adolescents is partially related to age and gender.

We evaluated 24-h time-domain heart rate variability (HRV) in 103 (46 females) healthy children and adolescents. Subjects were divided into four male and four female groups (ages 1-5, 6-10, 11-15, 16-20 years) and 24-h ambulatory Holter monitoring was performed. HRV was assessed by SDNN, SDNN index (SDNN-i), SDANN, rMSSD, pNN50. Males showed SDNN and SDANN values significantly higher than females while for SDNN-i, rMSSD, pNN50 there were no significant differences between sexes. With increasing age, there is a progressive and significant decrease of HR and increase of SDANN. On the other hand, SDNN, SDNNi, pNN50 and rMSSD increased significantly only between the first two age-groups. rMSSD and pNN50 were significantly related to body mass index. Thus, SDNN and SDANN, overall HRV measures, increased with age and were gender-related. HRV indices of parasympathetic function (rMSSD, pNN50) and SDNN-i increased up to 10 years of age and were gender-unrelated. These data demonstrate that in healthy children and adolescents there is a progressive modification of HRV that may reflect a progressive evolution of the autonomic nervous system, with different pattern measure-dependent. This paper enables us to compare, in future works, HRV in pediatric subjects in different groups according to the different HRV measures under examination.

Adolescent↗
PubMed2001

Placebo affects the performance of rats in models of depression: is it a good control for behavioral experiments?

Experimental design of behavioral studies in animals generally includes placebo-treated controls. However, when placebo is administered by injection in experimental models of psychiatric diseases such as depression, where stress may affect the execution of the behavioral test, it is possible that injection per se may influence the behavioral response. Rats injected with clomipramine hydrochloride (1, 10 or 50 mg/kg), as compared to animals injected with physiological saline as placebo, showed a dose-dependent decrease of the immobility time in the despair test and of the number of floor units explored in the open field in the reserpine test. However, when animals injected with placebo or clomipramine 50 mg/kg were compared with untreated intact controls, it was found that the immobility time in the despair test was higher in the placebo-treated animals than in untreated intact controls. A difference was found between clomipramine-injected animals and untreated intact controls. In contrast, rats tested in the reserpine test, which is based on repeated drug injections, no difference was found between placebo-treated animals and untreated intact controls. These results indicate that stressful procedure of the experimental design may change the response of animals in behavioral tests. Studies with experimental models of depression, where stressful procedures are used, should include a control group of untreated intact animals.

Animals↗