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Biomedical subjects

F Drago

Publications and source records attributed to F Drago.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Mid-term clinical condition and prognosis in adrenergic ventricular tachycardia in children with apparently normal hearts].

INTRODUCTION: Ventricular tachycardia is the most common diagnosis among children with exercise or emotion-related syncope. The aim of the study was to assess the prognosis and the clinical course of children, without long QT syndrome, with exercise-related ventricular tachycardia and apparently normal heart. METHODS: Since January 1984, we studied 14 children (mean age 9.7 +/- 3.8 years) with exercise-related ventricular tachycardia, and, at the initial detection, without demonstrable heart disease, as assessed by clinical evaluation, electrocardiogram and mono-bidimensional echocardiogram. Six patients had exercise related syncope, 1 exercise intolerance and 7 were asymptomatic. All patients underwent exercise testing on treadmill and 24-hour ECG monitoring. All patients were treated with antiarrhythmic drugs. All patients were tested by exercise testing and 24 hour ECG monitoring, alternatively, every six months, during therapy or after complete wash-out of the drug used. RESULTS: Ventricular tachycardia, detected by exercise testing and Holter monitoring, was polymorphic in 4 symptomatic patients, monomorphic with left bundle branch block morphology and inferior axis in the others. The mean rate of monomorphic ventricular tachycardia was 224 +/- 35 bpm in the symptomatic children and 180 +/- 33 bpm in the others (p = 0.03). Successful chronic treatment was achieved with beta-blockers in 5 cases, propafenone in 6, sotalol in 2 and flecainide plus metoprolol in 1. During follow-up (6 +/- 2.7 years), 1 patient with polymorphic ventricular tachycardia, on therapy, suddenly died during exercise, the other symptomatic patients had no variation of their arrhythmia on routine tests, except 1 who, after propafenone was stopped, had ventricular fibrillation during exercise testing. Among the 7 asymptomatic patients, 5 had no evidence of ventricular tachycardia on routine test after 2 +/- 3 years; the others had no variation of their treatment. CONCLUSION: Exercise related ventricular tachycardia in children seems: 1) to have more severe prognosis if symptomatic or polymorphic; 2) mostly to arise from right ventricle; 3) to be successfully treated by antiarrhythmic drugs with beta-blocking activity.

Adolescent↗
PubMed1996

Behavioral and neurochemical alterations induced by reversible conductive hearing loss in aged male rats.

Eighteen months old male rats of the Sprague-Dawley strain were subjected to a reversible conductive hearing loss (HL) or a sham operation. A series of behavioral tests performed 3 months after surgery, revealed a sustained deficit in learning and memory capacity and a marked depressive attitude of rats with HL. At this time, a group of these animals were allowed to recover from HL for 1 month and were again tested behaviorally compared to those with persistent auditory deficit. A better performance at the active and passive avoidance tests and normal responsiveness to the despair test was found in animals with recovered hearing capacity as compared to those with persistent HL. A biochemical analysis revealed a decrease of dopamine and homovanillic acid content and of choline-acetyltransferase and acetylcholinesterase activity in the striatum and hippocampus of animals with persistent HL as compared to those with recovered auditory deficit. These data suggest that persistent auditory deafferentation affects cognitive mechanism in old rats in a reversible manner.

Aging↗
PubMed1996

Vestibular compensation in aged rats with unilateral labyrinthectomy treated with dopaminergic drugs.

Drugs acting as agonists (SKF38393 and quinpirol) or antagonists (SCH23390 and sulpiride) on dopamine receptors were administered at various doses (1, 2 or 4 mg kg-1 day-1) to aged male rats of the Sprague-Dawley strain subjected to labyrinth unilateral lesion. The time course of vestibular compensation was evaluated by recording spontaneous eye nystagmus and by scoring ambulation and rearing with the open field test and motor ability and coordination with the rotorod test. Treatment started 3 days prior to surgery and continued until day 7 after surgery. The vestibular compensation of untreated young male rats was also studied with the same methods. The decline of spontaneous nystagmus in aged animals was slower than that of young rats and was facilitated by the large doses of quinpirol (D2 receptor agonist) and inhibited by sulpiride (D2 receptor antagonist) 4 mg kg-1 day-1, while the other drugs did not affect this parameter. After operation, ambulation and rearing of aged rats increased more slowly as compared to that of young animals. Moreover, motor performance and coordination in aged rats improved less rapidly than those of young controls. Dopamine receptor agonists increased ambulation and improved motor performance and coordination in aged rats, while dopamine receptor antagonists exerted opposite effects. Rearing was not affected by any kind of drug treatment. These results suggest that dopamine neurotransmission plays a role in vestibular compensation process following unilateral labyrinthectomy in aged animals, and this may have clinical relevance in vestibular pathologies of peripheral origin that are associated to brain ageing.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1996

Behavioral effects of amylin injected intracerebroventricularly in the rat.

Amylin is a peptide of pancreatic origin that has been reported to possess high-affinity binding sites in the brain and to affect central dopaminergic and serotonergic neurotransmission. Administered ICV the peptide induced a dose-dependent decrease of locomotor activity without affecting grooming and sniffing. At a dose of 5 micrograms/ rat, it antagonized the hypermotility and stereotypies induced by s.c. injection of amphetamine (2 mg/kg) or of the dopamine receptor agonist, apomorphine (250 mg/kg). Amylin did not change significantly the effect of haloperidol (0.5 mg/kg, s.c.) on locomotor activity, grooming, and sniffing. Moreover, the peptide did not modify the locomotor behavior of animals injected with the 5-HT2 antagonist, ritanserin (2 mg/kg, s.c.). These results suggest that amylin may exert motor effects, probably by interfering with central dopaminergic neurotransmission.

Amphetamine↗
PubMed1996

Behavioral and endocrine effects of growth hormone administration in aged female rats.

Growth hormone (GH) secretion declines during normal aging along with reproductive activity in mammalian species. Various behavioral changes also occur in aged animals. In these experiments we have studied the effects of GH administration on behavioral and endocrine alterations exhibited by aged (18 months old) female rats of the Sprague-Dawley strain. Animals were selected showing at least 2 weeks of cornified vaginal smears (constant estrous) and treated with GH (0.1 mg/kg SC) daily for 8 weeks. Vaginal smears performed during the drug treatment revealed a recovery of estrous cycle in 60% of animals. GH treatment was also followed by an increased acquisition of shuttle-box active avoidance behavior and a facilitated retention of passive avoidance response. Compared to saline-injected controls, female rats treated with GH also exhibited a decrease of novelty-induced excessive grooming. The endocrine pattern of GH-treated aged female rats revealed a decrease in plasma prolactin levels and an increase in luteinizing hormone and 17 beta-estradiol levels as compared to those of control animals. These results support the concept that behavioral and endocrine alterations occurring in aging are not irreversible and that GH may interfere with these changes probably by means of its trophic action on different target organs.

Aging↗
PubMed1996

Reciprocating supraventricular tachycardia in children: low rate at rest as a major factor related to propensity to syncope during exercise.

Reciprocating supraventricular tachycardia may have several clinical presentations, with symptoms often more severe during exercise or emotional stress. This study shows by using transesophageal atrial pacing, the factors related to syncope during exercise. Between May 1989 and June 1994, transesophageal atrial pacing was performed at rest and during exercise in 75 children aged > 6 years with suspected or documented episodes of paroxysmal supraventricular tachycardia. Reciprocating supraventricular tachycardia could be induced both at rest and during exercise in 22 patients (8 girls, 14 boys; mean age 10.6 +/- 2.7 years, range 7 to 15 years) with ventriculoatrial interval < 70 msec in 11 patients and > 70 msec in 11. At rest, all patients had palpitations caused by the induction of tachycardia. After conversion to sinus rhythm, when tachycardia was induced during exercise, symptoms did not change in 14 patients (group A), whereas symptoms worsened (presyncope) in eight (group B). The statistical analysis showed a significant difference of mean reciprocating supraventricular tachycardia rate at rest between the two groups (group A, 211 +/- 23 beats/min; group B, 173 +/- 33 beats/min; p = 0.0057) and reciprocating supraventricular tachycardia rate variation from rest to exercise (group A, 62 +/- 18 beats/min; group B, 105 +/- 24 beats/min; p = 0.0001). These data suggest that children with low tachycardia rate during normal activities may have syncope more frequently, independently of the tachycardia rate during exercise or emotional stress.

Adolescent↗
PubMed1996

Reactivity of 62 Rh MAbs with weak and variant antigens.

We characterized serologically 5 anti-C (4 IgM and 1 IgG), 3 anti-c (2 IgM and 1 IgG), 4 anti-E (1 IgM and 3 IgG), 4 anti-e (3 IgM and 1 IgG) and 46 anti-D (16 IgM and 30 IgG) monoclonal antibodies, provided by the Rh Section of the Third International Workshop and Symposium on Monoclonal Antibodies against Human Red Blood Cells and Related Antigens (1996) for their ability to detect weak and variant antigens. The agglutination patterns were established using untreated and papain-treated red blood cells in a column agglutination technology system (BioVue, Ortho). Significant differences were found between the IgM and IgG antibodies. The papain treatment seemed to be important for IgM but not for IgG antibodies. Almost all of the IgM anti-D antibodies detected untreated DIV samples and almost all of the IgG anti-D antibodies detected untreated weak D samples. Both IgM and IgG anti-D antibodies showed the highest number of negative reactions with DVI and Rh 33 red blood cells. The CwCw sample was detected by only one of the 4 anti-C IgM MAbs using enzyme-treated red blood cells. All anti-c MAbs were able to detect treated Cx samples. Because of the small number of weakly expressed E and e samples, definitive conclusions cannot be drawn on the ability of these antibodies to detect these antigens.

Antibodies, Monoclonal↗
PubMed1996

Hysterical neurosis of the conversion type: therapeutic activity of neuroleptics with different hyperprolactinemic potency.

To show a possible correlation between drug-induced hyperprolactinemia and improvement of hysterical neurosis of the conversion type, we followed 18 patients monitoring clinical somatic and psychic symptoms as well as serum prolactin levels. Six patients were treated with haloperidol and 12 with sulpiride; after 2 months sulpiride was administered at half the daily dose to 6 patients previously treated with the same drug. Clinical evaluation showed that sulpiride treatment led to a greater improvement compared to the haloperidol group. The different effectiveness of treatment could be explained by the different hyperprolactinemic potency. The therapeutic efficacy of neuroleptics suggests also that hyperactivity of dopaminergic transmission is involved in the pathophysiology of hysterical neurotic symptoms.

Adult↗
PubMed1996

[Transcatheter radiofrequency ablation in supraventricular tachycardia in children: immediate results and mid-term follow-up].

OBJECTIVES: The purpose of this study was to evaluate the efficacy and safety of radiofrequency ablation of supraventricular tachycardias due to a reentry circuit in a group of closely followed-up pediatric patients. PATIENTS: Forty-six pediatric patients (mean age 12.6 years, range 3-18) underwent a total of 48 radiofrequency ablation procedures for reciprocating supraventricular tachycardia. Thirty-nine had an orthodromic reentry tachycardia, 6 an atrioventricular node reentry tachycardia and 1 a permanent junctional reciprocating tachycardia. METHODS: To ablate the overt accessory pathways, the Kent potential (K) was identified and then the shortest A-K, and delta wave-K intervals were measured. The shortest V-A interval was identified for those concealed. For the left-sided accessory pathways, we used the retrograde transaortic approach in 10 procedures and the transseptal approach in 18. Atrioventricular node reentry tachycardia was ablated at the site where the slow-pathway electrogram was recorded. Follow-up clinical data, electrocardiogram, 24-hours Holter monitoring and transesophageal atrial stimulation were obtained and evaluated. RESULTS: Early: We performed a total of 48 procedures. Among 41 procedures performed in the 39 patients with accessory pathway, 38 were successful (92,6%). Mean fluoroscopy time was 31 +/- 18 min. For left sided accessory pathways, mean fluoroscopy time of procedures with retrograde approach was 45 +/- 10 min and with transseptal 23 +/- 12 min (p < 0.01). Ablation of slow-pathway in patients with intranodal reentry tachycardia was successful in 3/6 cases (50%). The patient with permanent junctional reciprocating tachycardia was successfully ablated. Late: All patients are alive and none was lost during the follow-up after a mean time of 12.9 months (range 5-33). Success at last follow-up was 100% in patients with an accessory pathway and 33% in patients with atrioventricular node reentry. In patient with permanent junctional reciprocating tachycardia, the arrhythmia appeared again one month after the procedure, thus a second successful attempt was performed. COMPLICATIONS: Major complications (6,5%) including a right femoral vein thrombosis (one patient), an hematoma without pulse loss (one patient) and a non-sustained monomorphic ventricular tachycardia (one patient). CONCLUSIONS: Our data show high efficacy of radiofrequency ablation in pediatric patients with accessory pathways. The risks are low at follow-up evaluation, but might be helpful a longer-term follow-up in order to evaluate the risk of a long fluoroscopy time and the arrhythmogenic effect of the scar.

Adolescent↗
PubMed1996

Epstein-Barr virus-related primary cutaneous amyloidosis. Successful treatment with acyclovir and interferon-alpha.

Cutaneous lesions related to chronic active Epstein-Barr virus (EBV) infection have been rarely documented in immunocompetent patients. A 30-year-old woman, fulfilling the diagnostic criteria for the chronic fatigue syndrome, had a 10-year history of pruritic brownish macules and papules on her chest and back. Her EBV serology was abnormal; the EBV genome was present in the epidermis of lesions, in oral secretions, and in peripheral mononuclear cells (PMC). Her blood lymphocytes spontaneously outgrew in culture. Histology revealed deposits of amyloid in the papillary dermis. Treatment with acyclovir and interferon-alpha rapidly improved her condition, stopped the lymphocyte outgrowth in culture, and reduced the EBV DNA content in oral secretions and in PMC. These data support an endogenous reactivation of EBV infection and suggest a causal relationship with primary amyloidosis.

Acyclovir↗
PubMed1996

[Idiopathic recurrent ventricular tachycardia in children: characteristics and long-term prognosis].

BACKGROUND: The aim of this study was to assess the prognosis and the clinical course of incessant idiopathic ventricular tachycardia (VT) with left bundle branch morphology, in a group of 14 children consecutively evaluated in our institutions between 1983 and 1994. METHODS: Mean age of these patients was 8 +/- 2 years, and they were followed for 56 +/- 32 months. In all the children, VT was present for more than 80% of the day, in non sustained runs. The mean rate of VT was of 142 +/- 30 beats/min. Four children were symptomatic. The evaluation of these children was obtained by treadmill stress test (12/14), cardiac catheterization (13/14), electrophysiologic study (10/14), nuclear magnetic resonance (7/14), and serial echocardiographic and Holter examinations. RESULTS: Right ventricular dysplasia was suspected in 2 cases on the basis of nuclear magnetic resonance and angiographic data. In both these cases VT was not suppressed by exercise. Medical treatment was started in 9/14 patients (69%), it was completely effective in 4 (44%) and partially effective in 2 further cases (22%). Thirteen out of fourteen patients had a regular follow-up. No patient died. All patients remained asymptomatic and in 6 (46%) VT disappeared. In 4 of these last 6 patients therapy has been previously effective. Two children, one with right ventricle dysplasia, continue antiarrhythmic treatment. CONCLUSIONS: Incessant VT is well tolerated in pediatric age. The frequency of spontaneous remissions is relatively high (46% of cases). In few patients this arrhythmia is associated with evident cardiac abnormalities. In our opinion, medical treatment is necessary in symptomatic patients and in those with heart abnormalities.

Angiocardiography↗
PubMed1995

Persistent erythema multiforme: report of two new cases and review of literature.

Within the clinical spectrum of erythema multiforme, two subgroups have been recently identified: recurrent erythema multiforme and the rare persistent erythema multiforme. Two additional cases of persistent erythema multiforme are described. Lesions were widespread and resistant to traditional therapies. One of the patients had an underlying malignancy; the other exhibited a symptom complex characterized by fatigue, fever, sore throat and lymphadenopathy, and an abnormal Epstein-Barr virus serologic profile suggestive of endogenous reactivation of Epstein-Barr virus infection.

Adult↗
PubMed1995

Biochemical changes induced by pyrphenoxone in the lens of rabbits and rats.

The xanthomatine analogue, pyrphenoxone, which is known to diminish the incidence of cataract in animals and in man, was applied in two different in vivo models of cataract induced in rabbits by tryptophan-free dietary regimen and in rats by hypergalactosemic diet. The drug was also applied at different concentrations in an in vitro model of cataract. It was found that soluble proteins and sulphurated amino acids of the lens in all in vivo and in vitro models of cataract were higher after pyrphenoxone was applied. Furthermore, the drug treatment was followed by a dose-dependent increase in reduced glutathione content in the lens of rabbits and rats. The same was found in the in vitro model of cataract. These results suggest that pyrphenoxone may act by inducing various biochemical changes that lead to a protection of lens against oxidative processes.

Animals↗