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Biomedical subjects

R Ferri

Publications and source records attributed to R Ferri.

At least 73 records · Page 4Linked to original sources
PubMed1995

Molecular contributions to cerebral cortical specification.

Evidence is accumulating that decisions of cell fate and commitment to specific regional phenotypes in the cerebral cortex occur through cell interactions that likely begin early in development, perhaps in the proliferative zone. We have focused on the development of the limbic cortex in rats, which includes areas involved in both cognitive and autonomic functions and is marked by expression of the limbic system-associated membrane protein. Transplantation studies show that precursor cells are sensitive to environmental cues which can control expression of area-specific phenotypes, including limbic system-associated protein synthesis and connectivity patterns, but early postmitotic neurons faithfully express traits based on their origin in the donor. We have studied this sensitive period of decision making in vitro. Molecules from the epidermal growth factor family influence dramatically the fate of precursor cells, but only in the presence of matrix molecules. In vivo, both the epidermal growth factor receptor and collagen type IV are expressed in the progenitor cell pool indicating that they can directly affect the initial decisions in differentiation. We suggest that early patterns of gene expression, influenced by environmental cues, are likely to provide a specific framework for subsequent decisions that lead to establishing cortical areas.

Animals↗
PubMed1995

Age, sex and mental retardation related changes of brainstem auditory evoked potentials in Down's syndrome.

Brainstem auditory evoked potentials (BAEPs) were recorded in 51 Down's syndrome (DS) subjects and compared with those of 38 normal controls; the correlations between the BAEP measures and age, sex, and degree of mental retardation were then evaluated. The DS patients showed a significant reduction in wave V latency and amplitude and in I-III, III-V, and I-V interpeak intervals. An age-related shortening of the I-V interpeak interval found in DS patients was interpreted as being a result of changes in central inhibitory/excitatory mechanisms. In both groups, female subjects presented an I-V interval shorter than that of males but this difference was greater in the DS subjects than in the normal population. The DS patients with severe mental retardation showed significantly longer I-V interpeak intervals than those with moderate retardation; this could be due to the presence of additional central nervous system abnormalities.

Adolescent↗
PubMed1995

Topographic EEG mapping of 3/s spike-and-wave complexes during absence seizures.

Topographic color mapping has recently been introduced for the study of ictal EEG manifestations of absences. We recorded 2-4 3/s spike-and-wave (sw) bursts in 12 patients with absence epilepsy, and performed a spectral analysis of the EEG under baseline conditions and during the 2 sec preceding the 3/s sw bursts. An increase in delta and theta bands was found in preseizure conditions. Moreover, the serial mapping of the sw complexes showed a different field distribution of the various components when the first sw was compared with the subsequent ones. In particular, the negative peak of the spike was mainly frontal during the first complex, with a tangentially oriented dipole, but it became better represented over the midline in the following sw, with a radially oriented dipole. We conclude that EEG changes can be detected before the onset of 3/s sw activity in absences, and that they are probably related to the strong inhibitory mechanisms acting in this type of seizure; moreover a frontal cortical mechanism seems to be prevalently active at the beginning of the seizure, which is soon captured by a cortico-subcortical process as the attack progresses.

Brain↗
PubMed1995

Seizures in Klinefelter's syndrome: a clinical and EEG study of five patients.

In this study, we report the cases of five unrelated patients with Klinefelter's syndrome and seizures or EEG epileptiform abnormalities; the karyotype was 47,XXY in four, and 47,XXY/46,XX in one. They were aged 13-25 years and followed up both clinically and by means of EEG. Two of the patients had epilepsy, one had only one isolated generalized tonic-clonic seizure, one had febrile convulsions and one presented focal epileptiform EEG abnormalities without seizures. In two of the patients, it was possible to classify the epilepsy (childhood epilepsy with occipital paroxysms and cryptogenic or symptomatic generalized epilepsy). Although the electroclinical patterns appeared to be rather heterogeneous in our patients, it is possible to infer the relative good evolution of seizures in Klinefelter's syndrome.

Adolescent↗
PubMed1995

Clinical and neurophysiological aspects of epilepsy in subjects with autism and mental retardation.

Clinical and neurophysiological findings for 28 patients with mental retardation, autism, and epilepsy were described. Correct classification of seizure type and epileptic syndrome (when possible), etiology, severity of autism and epilepsy, EEG findings, and neuroimaging findings were given. No particular epileptic syndrome was found to be more frequently correlated to autism, severity of autism was not correlated with a more pronounced tendency to develop seizures, and females with autism were more frequently affected by seizures than were males. In conclusion, the risk for epilepsy does not seem to be correlated to autism itself, but the same noxious event induces autism and epilepsy. The severity of epilepsy is strictly correlated with its etiopathogenetic mechanisms.

Adolescent↗
PubMed1995

Interferon alpha treatment of relapsing-remitting multiple sclerosis: long-term study of the correlations between clinical and magnetic resonance imaging results and effects on the immune function.

Interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) are proinflammatory cytokines which may be involved in the pathogenesis of MS. IFN-alpha counteracts many of the proinflammatory actions of IFN-gamma and TNF-alpha. We treated 20 patients with relapsing-remitting (RR) MS with 9 MIU of recombinant IFN-alpha-2a (rIFN-alpha) (n = 12) or placebo (n = 8) intramuscularly every other day for 6 months. Clinical exacerbations or new or enlarging lesions at serial MRI occurred in 2/12 rIFN-alpha-treated and in 7/8 placebo-treated patients (P < 0.005). Only one new MRI lesion was detected in the rIFN-alpha group, while 27 new or enlarging lesions were detected in placebo group (P < 0.01). Baseline lymphocyte IFN-gamma (19.10 +/- 7.12 U ml-1) and TNF-alpha (18.05 +/- 5.34 pg ml-1) production significantly decreased to 3.03 +/- 0.66 (P < 0.04) (for IFN-gamma) and to 5.78 +/- 0.90 (P < 0.04) (for TNF-alpha) after rIFN-alpha treatment. IFN-gamma and TNF-alpha production was unchanged in the placebo group. rIFN-alpha was tolerated without drop-outs or serious side-effects, but fever, malaise, fatigue (interfering with daily activities in two patients) and leukopenia frequently occurred. High-dose chronic systemic rIFN-alpha might reduce clinical and MRI signs of disease activity in RRMS. The changes in cytokine production suggest that the effect is probably mediated by a down-regulation of proinflammatory cytokine.

Adolescent↗
PubMed1994

Evoked spikes and giant somatosensory evoked potentials in a patient with fragile-X syndrome.

We report the case of a 7 year old boy with fragile-X syndrome and epilepsy. In this patient, the detection of rolandic epileptiform potentials during sleep and hand tapping-evoked rolandic EEG spikes, together with giant somatosensory evoked potentials, further support the already suggested neurophysiological similarities between fragile-X syndrome and benign childhood epilepsy with centrotemporal spikes.

Child↗
PubMed1994

BIT-mapped somatosensory evoked potentials in the fragile X syndrome.

Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in ten male patients with the fragile X (fraX) syndrome and nine normal controls. One fraX patient was found presenting the so-called "giant" MLSEPs with an amplitude of N60 of about 60 microV and of 40 microV after stimulation of the right and left median nerves, respectively. Tapping of the right hand, in the same patient, induced the appearance of left parietal evoked EEG spikes. These findings further support the already suggested similarity between the epileptic picture of several fraX patients with that of the benign childhood epilepsy with centrotemporal spikes. Color mapping of the MLSEPs recorded in the remaining nine patients, when compared with the control group, showed an abnormally large N30 over the frontal regions, together with an increase in amplitude of P27, over the parietal areas, and of N60 and P100 which also presented abnormal field distributions, being represented preferentially over the frontal regions. These data could suggest the existence of a cortical dysfunction mostly involving the frontal lobes (supplementary motor area, in particular) in the fraX syndrome which could support many behavioral changes usually observed in these patients.

Adolescent↗
PubMed1994

Bit-mapped somatosensory evoked potentials in Down's syndrome individuals.

Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in 19 patients with Down's syndrome (DS), in 13 age-matched normal controls and in 11 aged normal individuals. DS patients showed an increase in amplitude of P22, N30, P45, and N60. P100 latency was significantly shortened. After this potential, DS subjects showed the occurrence of a high voltage negative potential at around 100-110 msec followed by another high-voltage positive deflection; both these components showed a frontal-central distribution and were not observed in the two control groups. MLSEPs of DS subjects show peculiar alterations which could be supported by particular neurometabolic and/or neuropathologic changes.

Adolescent↗
PubMed1994

Giant somatosensory evoked potentials and pathophysiology of hyperekplexia. Neurophysiological study of one patient.

EEG during wakefulness and sleep and somatosensory evoked potentials from the median nerve were recorded in a 3 year-old boy with hyperekplexia and his close relatives (parents and two sisters). Centro-temporal spikes during sleep were found in the patient and in the older sister, while somatosensory evoked potentials, in the patient, showed abnormally high amplitude over the centroparietal regions. Pathophysiological mechanisms of hyperekplexia are discussed and the existence of symptomatic forms is suggested.

Child↗
PubMed1994

B-scan echographic measurement of endobulbar foreign bodies.

Echography plays an important role in symptomatology investigations of ocular traumatology. Trauma causes the opacification of eye fluids, and so echography is particularly suitable for studying the endobulbar situation. We wished to enrich ocular investigations with another methodology: ultrasonic evaluation of the dimensions of intraocular foreign bodies, and report here the results obtained with experimental studies introducing foreign bodies into enucleated bovine eyes.

Animals↗
PubMed1994

Chronic systemic high-dose recombinant interferon alfa-2a reduces exacerbation rate, MRI signs of disease activity, and lymphocyte interferon gamma production in relapsing-remitting multiple sclerosis.

We report a randomized, double-blind, placebo-controlled pilot trial of systemic high-dose recombinant interferon alfa-2a (rIFNA) in 20 patients with relapsing-remitting (RR) multiple sclerosis (MS). Patients received 9 million IU rIFNA (n = 12) or placebo (n = 8) intramuscularly every other day for 6 months. Clinical exacerbations or new or enlarging lesions on serial MRI occurred in two of 12 rIFNA-treated and in seven of eight placebo-treated patients (p < 0.005). There was only one enlarging MRI lesion in the rIFNA group, whereas 27 new or enlarging lesions were present in the placebo group (p < 0.01). Baseline lymphocyte interferon gamma production of 19.10 +/- 7.12 IU/ml significantly decreased to 3.03 +/- 0.66 IU/ml (p < 0.04) in the rIFNA group, whereas production was unchanged in the placebo group. The rIFNA was tolerated without dropouts or serious side effects, but fever, malaise, fatigue (interfering with daily activities in two patients), and leukopenia occurred frequently. Neuropsychological tests excluded neurotoxicity. High-dose systemic rIFNA might reduce clinical and MRI signs of disease activity in RR MS and should be investigated in larger trials.

Adolescent↗
PubMed1993

Brainstem auditory evoked potentials in tuberous sclerosis.

Brainstem auditory evoked potentials were recorded in 4 subjects and pattern reversal evoked potentials in 1 subject, all with tuberous sclerosis. Alterations were found (absence or delay of components and prolonged interpeak intervals) which may suggest impaired nervous conduction also at brainstem level in patients with tuberous sclerosis.

Adolescent↗
PubMed1992

Tuberous sclerosis and Down syndrome: a casual association?

This paper reports on the clinical, neurophysiological and neuroradiological characteristics of a patient with Down syndrome unusually associated with tuberous sclerosis. In particular, epilepsy is investigated in detail and its polygraphic study and etiopathological factors are discussed. The most interesting findings are those related to the presence of a structural abnormality of the rolandic-parietal cortex, bilaterally, in the form of pachygyria.

Adult↗