Biomedical subjects

Patrizio Pasqualetti

Publications and source records attributed to Patrizio Pasqualetti.

6 recordsLinked to original sources

PubMed2003

Motor cortex excitability in Alzheimer's disease: a transcranial magnetic stimulation study.

Motor deficits affect patients with Alzheimer's disease only at later stages. Recent studies demonstrate that the primary motor cortex is affected by neuronal degeneration accompanied by the formation of amyloid plaques and neurofibrillary tangles. It is conceivable that neuronal loss is compensated by reorganization of the neural circuitries occurring along the natural course of the disease, thereby maintaining motor performances in daily living. Cortical motor output to upper limbs was tested via motor-evoked potentials from forearm and hand muscles elicited by transcranial magnetic stimulation of motor cortex in 16 patients with mild Alzheimer's disease without motor deficits. Motor cortex excitability was increased, and the center of gravity of motor cortical output, as represented by excitable scalp sites, showed a frontal and medial shift, without correlated changes in the site of maximal excitability (hot-spot). This may indicate functional reorganization, possibly after the neuronal loss in motor areas. Hyperexcitability might be caused by a dysregulation of the intracortical GABAergic inhibitory circuitries and selective alteration of glutamatergic neurotransmission. Such findings suggest that motor cortex hyperexcitability and reorganization allows prolonged preservation of motor function during the clinical course of Alzheimer's disease.

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PubMed2002

Enhancement patterns of prostate cancer in dynamic MRI.

Our objective was to analyze fast-field-echo dynamic subtracted (FFE/DS) MRI data in prostate cancer, in order to recognize enhancement patterns of tumoral tissue in comparison with non-tumoral peripheral prostatic tissue. Eleven consecutive patients with prostate cancer were proposed for radical prostatectomy. Before surgery, all patients underwent endorectal coil MRI examination. In addition to standard sequences, a dynamic study was performed by FFE/DS to evaluate tumoral behavior after Gd-DTPA rapid infusion. Analysis of the imaging was made by the means of the time/signal intensity curve obtained during early contrast medium enhancement, sampling both the abnormal enhancing focal area and the opposite lobe at the level of the main prostatic tissue. A focal area of increased enhancement was observed in the site of the tumor in all cases. The time/intensity curve sampled on this area and compared with the opposite lobe demonstrated a high confidence interval of the difference of the data: mean tumor maximal intensity 1331 (SD 187) vs normal 470 (SD 139) and mean tumor rise time 103 s (SD 30) vs normal 250 (SD 38; p<0.01). In tumoral tissue, the enhancement percentage of signal intensity (SI%=pre-contrast minus post-contrast/pre-contrast x100) was 316.7%. At FFE/DS, there is a typical behavior of the time/intensity curve of contrast enhancement in prostatic cancer that might be employed in diagnosis of the disease.

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PubMed2002

Red blood cell copper, zinc superoxide dismutase activity is higher in Alzheimer's disease and is decreased by D-penicillamine.

Copper, zinc superoxide dismutase (Cu, Zn SOD) activity was measured in red blood cells (RBC) of 32 patients affected by Alzheimer's disease (AD), eight other AD patients treated with the copper-chelating agent D-penicillamine, 13 first-degree relatives and 22 controls. All AD patients enrolled in our study showed a higher level of Cu, Zn SOD activity early in the disease. No correlation between apolipoprotein E genotype and SOD activity was found in AD patients. D-penicillamine treatment of AD patients for 24 weeks lowered the enzyme activity even below the control value. These results support the hypothesis that a higher level of Cu, Zn SOD activity in RBC can be an early diagnostic peripheral marker of this disease and a sensor to monitor treatments with copper-chelating drugs.

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PubMed2002

Monthly corticosteroids decrease neutralizing antibodies to IFNbeta1 b: a randomized trial in multiple sclerosis.

Neutralizing antibodies (NAB) to interferon beta (IFNbeta) occur in some multiple sclerosis (MS) patients, particularly during the first year of treatment. The presence of NAB may be associated with an attenuation of the therapeutic effect. The aim of this study was to compare the frequency of NAB occurrence in patients treated with IFNbeta-1 b with that in patients treated with IFNbeta-1 b combined with monthly pulses of intravenous methylprednisolone (MP). One hundred and sixty-one patients with relapsing-remitting MS were randomized in two treatment arms: 8 MIU of IFNbeta- 1 b subcutaneously injected every other day either alone or in combination with 1000 mg of monthly intravenous MP. NAB were evaluated at baseline and at months 3,6,9,12 and 15 by the MxA assay in a specialized laboratory. Positivity was defined as a titer of > or = 20 neutralizing units according to two different definitions: I) one or more non-consecutive positive samples, II) at least two consecutive positive samples. NAB (definition I) were observed in 26.8% of patients in the IFNbeta-1 b alone arm and in 12.1% of patients in the combination therapy arm (p = 0.05 by the chi-square test), which corresponds to a relative reduction of 54.9%, whereas according to definition II, these figures dropped to 22.5 % for the IFNbeta-1 b alone arm, and 10.6% for the combination therapy arm (relative reduction 52.9%, p = 0.10, NS). A higher probability of remaining in the NAB-free status was observed in patients treated with the combination therapy (p = 0.031 for definition I and p = 0.o49 for definition II, by the Wilcoxon-Gehan test). Methylprednisilone combined with IFNbeta-1 b reduces the incidence of neutralizing bodies to in terferon-beta during the first year of treatment in MS patients.

Adjuvants, Immunologic↗

PubMed2002

Category-specific impairment in patients with Alzheimer's disease as a function of disease severity: a cross-sectional investigation.

Several questions about category specificity associated with lexical-semantic deficits in Alzheimer's disease (AD) patients are still being debated. In this study, we enrolled 53 AD patients and 30 normal control subjects to investigate the following issues: Is category specificity consistently associated with AD? Do AD patients show both possible patterns of category specific impairment, i.e. selective impairment for either living things or artifacts? Is the direction of the category specific effect predictable as a function of disease severity? Is a selective impairment for living things secondary to a disproportionate loss of perceptual knowledge? We found an overall advantage for artifacts even when controlling for several confounding factors. We did not find any relation between direction of category specificity and severity of the disease or between category specificity and loss of knowledge about perceptual or functional attributes.

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PubMed2002

Mini-mental state examination and mental deterioration battery: analysis of the relationship and clinical implications.

OBJECTIVES: To explore the associative structure between a screening test for dementia, the Mini-Mental State Examination (MMSE), and a neuropsychological battery for the detection of dementia, the Mental Deterioration Battery (MDB). DESIGN: A retrospective analysis. SETTING: Psychology unit of a general hospital in Rome, Italy. PARTICIPANTS: Three hundred consecutive outpatients and inpatients referred to our hospital on the basis of suspected cognitive impairment and evaluated between January 1999 and March 2000. MEASUREMENTS: MMSE and MDB. RESULTS: Of the 300 subjects evaluated by the MMSE score, 142 (47.3%) were considered to be cognitively healthy, and 116 (38.7%) were mildly and 42 (14.0%) moderately impaired. Factor analysis of MDB extracted three factors able to account for 75% of the total variance: a visuospatial factor, verbal memory ability, and a language skill. Using MMSE as an independent variable, a linear regression model could account for the visuospatial and language factors and a cubic regression model for the verbal memory factor. Within the normal MMSE boundaries (24-30), a dramatic decrease of verbal memory could be documented, whereas the slope is less steep in the mild impairment group (16-23). CONCLUSIONS: Our findings indicate the presence of a warning range within the normal MMSE interval. Thus, the traditional MMSE cutoff values may not be appropriate in detecting early phases of dementia. When patients score about 27 on MMSE, it should be of interest to check whether they fail only on long-term memory tests, because this could be a first signal of a preclinical condition heralding clear dementia (e.g., mild cognitive impairment).

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