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Biomedical subjects

P Bonanni

Publications and source records attributed to P Bonanni.

At least 37 records · Page 2Linked to original sources
PubMed1999

No evidence of a major locus for benign familial infantile convulsions on chromosome 19q12-q13.1.

PURPOSE: A locus for benign familial convulsions (BFICs) has been recently mapped on chromosome 19q12-13.1 by studying five families of Italian descent. The main goal of this study was to investigate the role of this locus in a set of seven newly identified families with at least three affected cases. METHODS: Five polymorphic microsatellite markers covering the BFIC locus on chromosome 19q have been typed, and parametric linkage analysis has been performed to analyze the segregation of the BFIC locus within our families. RESULTS: Cumulative 2-point lod scores and multipoint analysis showed no evidence of linkage between chromosome 19 markers and the BFIC phenotype. The analysis of family-specific 2-point lod scores and haplotypes, however, indicated the presence of linkage to chromosome 19q in a single family, suggesting genetic heterogeneity within our family sample. CONCLUSIONS: Our study demonstrates that the previously reported BFIC locus on chromosome 19q12-13.1 is not a major locus for BFICs. We suggest that genetic heterogeneity may have generated our discordant linkage findings, as it was reported in benign familial neonatal convulsions, a related idiopathic mendelian syndrome.

Chromosome Mapping↗
PubMed1998

Cortical reflex myoclonus in Rett syndrome.

Rett syndrome (RS) is one of the most frequent causes of mental retardation in females. As there are no known biochemical, genetic, or morphological markers, diagnosis is based on clinical phenotype including severe dementia, autism, truncal ataxia/apraxia, loss of purposeful hand movements, breathing abnormalities, stereotypies, seizures, and extrapyramidal signs. Myoclonus, although reported in some series, has never been characterized. We studied 10 RS patients, age 3 to 20 years, and observed myoclonus in 9. Severity of myoclonus did not correlate with that of the other symptoms or with age. Multifocal, arrhythmic, and asynchronous jerks mainly involved distal limbs. Electromyographic bursts lasted 48 +/- 12 msec. Burst-locked electroencephalographic averaging generated a contralateral centroparietal premyoclonus transient preceding the burst by 34 +/- 7.2 msec. Motor evoked potentials showed normal latencies, indicating integrity of the corticospinal pathway. Somatosensory evoked potentials were enlarged. The C-reflex was hyperexcitable and markedly prolonged (62 +/- 4.3 msec), mainly due to increase in cortical relay time (28.4 +/- 4.5 msec). We conclude that RS patients show a distinctive pattern of cortical reflex myoclonus with prolonged intracortical delay of the long-loop reflex.

Adolescent↗
PubMed1998

Universal hepatitis B immunization: infant, and infant plus adolescent immunization.

Hepatitis B virus (HBV) is one of the world's most widespread infectious agents and the cause of millions of diseases and deaths each year. Vaccination programmes aimed at risk groups are important for individual protection, but will not eliminate viral transmission in Europe, since 70% of acute hepatitis B cases are either acquired by sexual activity or are of unknown origin. In industrialized countries, HBV infection occurs mainly in young adults, however, when the virus is acquired during infancy it leads to extremely high rates of chronic carriership, contributing disproportionately to the overall pool of HBsAg carriers. This explains why integrating universal HB vaccination into routine infant immunization programmes is the best means for controlling HB in countries with intermediate to high levels of HB endemicity. In countries of low endemicity, universal immunization of adolescents may be considered as an alternative to infant vaccination, as this strategy has a more rapid effect on the epidemiology of the infection. Where feasible, a double strategy (infant plus adolescent) is the optimal solution. With this strategy, adolescent immunization is necessary only for the time required for the first cohort of immunized infants to reach adolescence. After universal vaccination programmes have been implemented, efforts must be made to sustain vaccine procurement, monitor coverage, check the incidence of acute disease, particularly in immunized cohorts and verify by seroepidemiological studies the progression made in the elimination of HBV transmission.

Adolescent↗
PubMed1998

Success stories in the implementation of universal hepatitis B vaccination: an update on Italy.

Compulsory universal vaccination against hepatitis B was introduced in 1991 in Italy for all newborns and 12-year-olds. Despite the decreasing circulation of the virus noted in the late-1980s, it was clear that only universal immunization would control hepatitis B infection and limit the transmission of the virus. Data collected during the first six years after vaccination was implemented show the success of the strategy. Over 90% of infants in the country and adolescents living in north-central Italy were immunized. Since 1995, the decrease in acute cases of hepatitis B has accelerated in the age groups 0-14 and 15-24, particularly in two regions of the north; during the same period, no comparable decrease in incidence was seen in older age groups. Monitoring coverage of vaccination and incidence of acute disease and seroepidemiological studies will continue and should show a rapid progression towards the elimination of HBV circulation in the country.

Hepatitis B↗
PubMed1998

Experience of hepatitis A vaccination during an outbreak in a nursery school of Tuscany, Italy.

An outbreak of hepatitis A started in late October 1996 in a nursery school in Tuscany, Italy. A programme of hepatitis A vaccination without the use of immunoglobulin started at the beginning of December 1996 and included 33 children, 21 household contacts and 6 adults working in the school. Overall, 11 cases occurred in children attending the school (attack rate 27%) and 10 among their household contacts (attack rate 9 %). The latter also included parents, and, in two cases, grandmothers. The data indicate that susceptibility to HAV has increased over recent decades in central Italy. Past and recent experience shows that the usual duration of hepatitis A epidemics in the absence of immune prophylaxis is longer than that described here. The use of hepatitis A vaccine probably contributed to the early extinction of the outbreak, because no further cases were notified in the area after 7 February 1997.

Adult↗
PubMed1998

Myoclonic absence-like seizures and chromosome abnormality syndromes.

PURPOSE: We explored the relationship between myoclonic absence seizures (MAS) and underlying chromosome disorders. METHODS: Among 14 patients with MAS observed in three centers, 5 had typical cryptogenic myoclonic absence epilepsy (MAE), 2 had MAS associated with other seizure types (1 with signs of a neuronal migration abnormality and 1 with signs of a metabolic disorder), and 7 had MAS, with or without other seizure types, complicating a chromosome abnormality syndrome-2 with trisomy 12p, 4 with Angelman syndrome, and 1 with inv dup (15). RESULTS: In the 7 patients with chromosomopathy, MAS appeared at a mean age of 2.9 years (range 4 months to 6 years 6 months), had a duration of 4-20 s, and were accompanied by reduced awareness and rhythmic myoclonic jerks involving proximal limb muscles. Ictal EEG showed 2- to 3-Hz generalized spike-and-wave discharges. CONCLUSIONS: In these patients, MAS differed slightly from those of typical MAE: age of onset was earlier, absences were of shorter duration, and no clear increase in muscular tone was noted. Abnormal expression of genes codifying for the subfamily of K+ channels and for gamma-aminobutyric acid-3 subunit receptors (GABRB3), both located in the chromosome segments involved in the chromosomopathies presented by our patients, could be responsible for the same generalized seizure type. Chromosome analysis should be performed in patients with mental retardation and MAS, especially when the ictal pattern does not completely overlap that observed in MAE.

Adult↗
PubMed1998

Multilobar polymicrogyria, intractable drop attack seizures, and sleep-related electrical status epilepticus.

BACKGROUND AND OBJECTIVE: Patients with cortical malformations often have intractable seizures and are candidates for epilepsy surgery. Within an unselected series of patients with various forms of cortical malformation, nine patients with multilobar polymicrogyria had electrical status epilepticus during sleep (ESES) accompanied by infrequent focal motor seizures. Eight patients also had intractable atonic drop attack seizures. Because ESES usually is accompanied by a good long-term seizure prognosis, the objective of this study was to examine ESES outcome among patients with a structural lesion that is usually highly epileptogenic and has a low seizure remission trend. METHODS: The nine patients had follow-up periods lasting 4 to 19 years. All underwent brain MRI, serial sleep EEG recordings, and cognitive testing during and after ESES. RESULTS: ESES and drop attack seizures appeared between the ages of 2 and 5 years (mean, 4 years) and ceased between the ages of 5 and 12 years (mean, 8 years). At the last visit patients were 8 to 23 years of age (mean, 14.5 years) and were either seizure free or had very infrequent focal motor seizures during sleep. Three patients were free from antiepileptic drugs. In no patient was definite cognitive deterioration apparent after ESES in comparison with earlier evaluations. CONCLUSIONS: Age-related secondary bilateral synchrony underlying ESES may be facilitated in multilobar polymicrogyria. The good seizure outcome contrasts with that usually found in the presence of cortical malformations. For children with polymicrogyria and drop attack seizures, surgical treatment of the epilepsy should be considered cautiously, and sleep EEG recordings should be performed systematically.

Age of Onset↗
PubMed1997

Bilateral parasagittal parietooccipital polymicrogyria and epilepsy.

We describe 9 patients with a bilateral malformation of cortical development, centered around the parasagittal and mesial aspects of the parietooccipital cortex, with magnetic resonance imaging findings suggestive of polymicrogyria. No familial distribution or etiologic factors were identified. Location in a watershed area between anterior and posterior cerebral arteries suggests postmigratory perfusion failure as the underlying cause. In most patients the malformation was detected by magnetic resonance imaging after computed tomography scans with 10-mm-thick sections were considered normal. Seizures, present in all, had started between the ages of 20 months and 15 years (mean, 9 years) and were intractable in 7. Complex partial seizures with or without minor automatisms were the most frequent ictal pattern. In only 4 patients these were preceded by symptoms indicating posterior onset. Interictal electroencephalograms showed both diffuse and bilateral parietooccipital or temporal abnormalities. The range of IQ scores indicated average intelligence to mild retardation. Several patients presented deficits on neuropsychological tasks requiring performance under time constraints, suggesting that the malformation may result in cognitive slowing. Early diagnosis of this malformation may be difficult because of the lack of neurological signs, relatively late seizure onset, difficulty in localizing seizure onset, and inability to recognize the cortical abnormality on computed tomography scans.

Adolescent↗
PubMed1997

Delayed appearance of interictal EEG abnormalities in early onset childhood epilepsy with occipital paroxysms.

Childhood epilepsy with occipital paroxysms is an age-related idiopathic focal epilepsy. Occipital EEG paroxysms are considered necessary for diagnosis. We carried out a close clinical and EEG follow-up (range, 2-12 years; mean, 6 years 7 months; median, 7 years) in 24 patients (age range, 4-19 years; mean, 11 years 8 months; median, 11 years). In five children with early seizure onset and particularly benign prognosis without any treatment, EEG abnormalities appeared 3-10 months after the first seizure. Four of them exhibited the ictal pattern of versive seizures with vomiting. Our findings confirm that in the early idiopathic focal seizure disorders, interictal EEG abnormalities may be lacking at the beginning of the disorder.

Adolescent↗
PubMed1997

Adolescent onset of idiopathic photosensitive occipital epilepsy after remission of benign rolandic epilepsy.

PURPOSE: We describe 2 girls, aged 19 years, who experienced a rolandic seizure at ages 4 and 5, respectively, together with the interictal EEG features of benign rolandic epilepsy (BRE). In adolescence both patients developed photosensitive occipital seizures accompanied by spontaneous and photic-induced occipital EEG paroxysms. METHODS: We have been following 33 patients with a history of BRE, between ages 12 and 28 years (mean 17 years). Twenty-one of these patients had experienced their last rolandic seizure before the age of 10 years and 9 of them had been without treatment since age 11 or earlier. In 2 of these 9 patients, other types of seizures recurred after remission of BRE. Clinical, EEG, and evoked potential findings on these 2 patients are presented. RESULTS: After having experienced BRE, both patients suffered partial seizures from age 12, with elementary visual hallucinations, visual blurring, slow head turning, cephalic pain, epigastric discomfort, unresponsiveness, and vomiting. Seizure onset was related to watching TV or exposure to bright light. EEG showed interictal occipital spikes, and a photoparoxysmal response limited to the occipital lobes. Visual evoked potentials were greatly increased in amplitude. One patient had two visual attacks only and remained seizure free after 4 years of follow-up, while the other had seizures controlled by an association of valproate and carbamazepine. CONCLUSIONS: Clinical and neurophysiological characteristics suggest that these two patients may have presented different age-related expressions within the spectrum of a benign seizure susceptibility syndrome rather than sharply distinct epilepsy syndromes.

Adolescent↗
PubMed1997

Evaluation of performance of the RIBA processor system for automated analysis of the strip immunoblot assay for detection of antibodies to hepatitis C virus.

The performance of a new automated analyzer for the processing and interpretation of the RIBA Strip Immunoblot Assay (SIA), used in the diagnosis of hepatitis C virus (HCV) infection, was evaluated. Laboratory performance of the RIBA SIA was compared with that of two manually processed supplementary anti-HCV tests (RIBA HCV 3.0 SIA and INNO-LIA HCV Antibody III). Specificity of the automated processing of SIA was 100% for 90 selected anti-HCV-negative samples. On the other hand, 119 of 120 (99.2%) previously confirmed anti-HCV-positive samples were also positive when assayed on the automated processor. Results for all specimens except one (51 of 52) were concordant for manual and automated RIBA, while 15 of 68 sera tested with automated RIBA and the INNO-LIA assay showed different patterns of reactivity. Three HCV sensitivity panels and one seroconversion panel were also compared. The results show a high sensitivity for SIA NS3- and NS5-encoded antigens. Moreover, data obtained for the anti-HCV seroconversion panel and for samples with borderline or discordant anti-HCV enzyme-linked immunosorbent assay results suggest that bands with a relative intensity of >0.5 on the automated analyzer (theoretically negative) should be evaluated with care. Coefficients of variability ranged from 9 to 14.8% in an interassay reproducibility study. Overall, the performance of the automated analysis of SIA is comparable to that of the manual RIBA assay. The new automated processor for SIA bands proved to be sensitive and specific. Its use makes the optical scoring of bands unnecessary by indicating relative intensity values, which could be particularly useful in the follow-up care of anti-HCV-positive patients receiving antiviral therapy.

Electronic Data Processing↗
PubMed1997

Bilateral periventricular nodular heterotopia with mental retardation and syndactyly in boys: a new X-linked mental retardation syndrome.

Bilateral periventricular nodular heterotopia (BPNH) is a recently recognized malformation of neuronal migration, and perhaps proliferation, in which nodular masses of gray matter line the walls of the lateral ventricles. Most affected individuals have epilepsy and normal intelligence with no other congenital anomalies. A striking skew of the sex ratio has been observed because 31 of 38 probands have been female, and one gene associated with BPNH was recently mapped to chromosome Xq28. We report three unrelated boys with a new multiple congenital anomaly-mental retardation syndrome that consists of BPNH, cerebellar hypoplasia, severe mental retardation, epilepsy, and syndactyly. Variable abnormalities included focal or regional cortical dysplasia, cataracts, and hypospadius. We hypothesize that this syndrome involves the same Xq28 locus as isolated BPNH, and we review the expanding number of syndromes associated with BPNH.

Adolescent↗
PubMed1996

Cortical myoclonus in Angelman syndrome.

Angelman syndrome (AS) results from lack of genetic contribution from maternal chromosome 15q11-13. This region encompasses three GABAA receptor subunit genes (beta3, alpha5, and gamma3). The characteristic phenotype of AS is severe mental retardation, ataxic gait, tremulousness, and jerky movements. We studied the movement disorder in 11 AS patients, aged 3 to 28 years. Two patients had paternal uniparental disomy for chromosome 15, 8 had a >3 Mb deletion, and 1 had a microdeletion involving loci D15S10, D15S113, and GABRB3. All patients exhibited quasicontinuous rhythmic myoclonus mainly involving hands and face, accompanied by rhythmic 5- to 10-Hz electroencephalographic (EEG) activity. Electromyographic bursts lasted 35 +/- 13 msec and had a frequency of 11 +/- 2.4 Hz. Burst-locked EEG averaging in 5 patients, generated a premyoclonus transient preceding the burst by 19 +/- 5 msec. A cortical spread pattern of myoclonic cortical activity was observed. Seven patients also demonstrated myoclonic seizures. No giant somatosensory evoked potentials or C-reflex were observed. The silent period following motor evoked potentials was shortened by 70%, indicating motor cortex hyperexcitability. Treatment with piracetam in 5 patients significantly improved myoclonus. We conclude that spontaneous, rhythmic, fast-bursting cortical myoclonus is a prominent feature of AS.

Adolescent↗
PubMed1996

Low prevalence of diphtheria immunity in the population of Florence, Italy.

A seroepidemiological study was conducted in 1994 on a representative sample of the population of Florence in order to verify the immunity coverage against diphtheria. Subjects were divided according to sex and age class. Sera from each selected class were at least 1.5/1000 of the residing population. Diphtheria antitoxin was titrated using a quantitative ELISA test. The results show an overall adjusted prevalence of diphtheria immunity (> or = 0.01 IU/ml) equal to 63.7%. Subjects of younger age classes have good protection levels (85.5% immune under 30 years), while only half individuals aged > or = 50 years have antibody titres > or = 0.01 IU/ml. Full protection (antibody titre > or = 0.1 IU/ml) was detected only in a very small proportion of those aged > or = 40 years. Our data show (1) how a recrudescence of diphtheria could theoretically take place in older subjects living in Italy, and (2) stress the importance of periodical re-vaccination of adults.

Adolescent↗
PubMed1996

Analytical and laboratory evaluation of a new fully-automated third generation enzyme immunoassay for the detection of antibodies to the hepatitis C virus.

An analytical and laboratory evaluation of a newly-developed fully-automated third generation ELISA for the detection of anti-HCV (Cobas Core Anti-HCV EIA, Roche) was undertaken. Coefficients of variation (CVs) calculated on positive control and serum samples ranged from 5.9 to 9.8% in the intra-assay precision test and from 3.9 to 11.3% in the inter-assay evaluation. With regard to the study of clinical laboratory performance, five groups of sera pre-screened with two third generation ELISA (Ortho HCV 3.0 ELISA; Innotest HCV Ab III) were assayed: anti-HCV negative samples (n = 932); anti-HCV positive samples (n = 449); difficult sera of different origin (n = 113); sera with discrepant results in the two ELISAs (n = 50); sera with an indeterminate result in one or more confirmatory test (n = 34). The overall concordance between the Roche anti-HCV EIA and the two reference assays was 97.5 and 97.8% for the Ortho and for the Innogenetics assays, respectively. Although it is not possible to provide absolute figures for clinical sensitivity and specificity, the results of the study on discrepant samples show that the Cobas Core Anti-HCV gives a number of negative results with positive or indeterminate confirmatory anti-HCV tests, which is intermediate between the Ortho and the Innogenetics assay. In contrast, only 5% Cobas Core Anti-HCV reactive sera are not positive or clear-cut single band reactive by supplemental assays. The results show that the new fully-automated third generation anti-HCV test is a valid alternative to other commercially available assays for screening of antibodies to the hepatitis C virus.

Enzyme-Linked Immunosorbent Assay↗
PubMed1995

Evaluation of in vitro efficacy of the disinfectant Virkon.

A study was conducted on a new acid peroxygen system based disinfectant (Virkon), in order to assess its in vitro efficacy. The chemical was tested on different bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli), spores (Bacillus subtilis) and on the Hepatitis B surface antigen (HBsAg), and compared in its activity with phenol and glutaraldehyde (calculation of the 'phenol coefficient' and the 'glutaraldehyde coefficient'). The constancy of speed of disinfection, the coefficient of concentration, the minimal inhibitory concentration (MIC) were also determined, and the destruction of the HBsAg antigenic activity was studied using an ELISA kit. The sporicidal efficacy of Virkon was assessed by cultivating spores in agar nutrient after contact with different dilutions of the disinfectant. The results of the tests showed that Virkon has a high concentration coefficient (mean value of k: 0.374/min) and a wide range of action. The low MIC demonstrates how little concentrations of Virkon can inactivate all studied bacteria. The disinfectant was also able to destroy the hepatitis B surface antigen, and it demonstrated good activity against spores, especially if used in physiologic solution. These characteristics, coupled with the absence of initiation or toxic effects on animals showed by other studies, make wide fields of application for the new disinfectant foreseeable.

Animals↗