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Biomedical subjects

C Piccini

Publications and source records attributed to C Piccini.

15 recordsLinked to original sources
PubMed2005

Alzheimer's disease: role of size and location of white matter changes in determining cognitive deficits.

This study investigated the contribution that white matter changes (WMCs) make to clinical and cognitive features in Alzheimer's disease (AD), independently of possible confounders such as cortical atrophy and the apolipoprotein E genotype as well as their relationship to vascular risk factors. We semiquantitatively assessed the degree and location of WMCs (global, periventricular and deep white matter), lacunes and global atrophy on brain MRI scans of 86 AD cases, extensively evaluated from a clinical and neuropsychological point of view. Multivariate logistic and linear regression analysis showed that age was the only significant predictor of all WMC measures and revealed a significant association of periventricular WMCs with performance on executive function tasks as well as of deep WMCs with history of mood depression. Our results underline the significance of WMC location over size in the occurrence of specific cognitive deficits in AD.

Aged↗
PubMed2005

Corpus callosum atrophy is associated with gait disorders in patients with leukoaraiosis.

Cognitive impairment and gait disturbances are the most frequent clinical findings in patients with leukoaraiosis (LA). Corpus callosum (CC) atrophy has been associated with dementia in patients with LA, as well as with gait disturbances in patients with normal pressure hydrocephalus. We investigated, in patients with LA, the possible association between gait impairment and CC atrophy, taking into account cognitive deficits and the other brain lesions commonly present in these patients. Thirty patients (M:F=21:9; mean age 72.5+/-6.3 years) with gait disturbances and brain CT images consistent with LA underwent an assessment of gait and a cognitive assessment of global and selective functions. Magnetic resonance imaging (MRI) was used to measure thickness and area of the CC, total LA volume, lacunar infarcts and size of lateral ventricles. We examined the effect of every MRI change on each performance measure. Reduction of CC thickness, particularly that of the anterior segment, had a significant effect on severity of gait impairment, as measured using the gait scale's score. It was independent of any other brain changes revealed by MRI, including LA. An independent, significant association was also found between CC area and the Left Hand Praxis test results. In patients with LA, CC atrophy is associated with gait impairment independently of LA and other brain abnormalities usually present in these patients.

Aged↗
PubMed2001

Clinically relevant cognitive impairment after cardiac surgery: a 6-month follow-up study.

BACKGROUND AND PURPOSE: The majority of studies on neuropsychological complications after cardiac surgery used the raw variation of selective tests scores to define the occurrence of cognitive decline. We prospectively estimated the frequency of cognitive impairment after cardiac surgery, with a particular emphasis on persistent and clinically relevant cognitive decline. Possible baseline and operative predictors were also evaluated. METHODS: An extensive neuropsychological battery was administered to 110 patients (mean age 64.1+/-9.4 years; 70.9% males) undergoing cardiac surgery before and 6 months after the operation. After evaluating the variations in the cognitive performances, two independent neuropsychologists ranked the patients as unchanged-improved, mildly-moderately deteriorated, or severely deteriorated, using a global and functionally oriented judgement. The degree of the impairment was determined in relation to its impact on everyday life activities. RESULTS: Ten patients (9.1%) were ranked as severely deteriorated, 22 (20%) as mildly-moderately deteriorated, and 78 (70.9%) as unchanged-improved. Cognitively impaired patients were older (p=0.031), more often females (p=0.005), with a low education level (p=0.013). At multivariate analysis, female gender (odds ratio (OR) 6.14, 95% confidence interval (95% CI) 2.16-17.50), baseline use of beta-blockers (OR 4.55, 95% CI 1.30-15.92), and PaO2 at arrival in intensive care unit (OR for 1 mm Hg increment 1.012, 95% CI 1.004-1.020) were significant predictors of cognitive impairment of any degree. Positive predictors of severe cognitive impairment were history of hypertension (OR 5.33, 95% CI 1.03-27.64) and PaO2 at arrival intensive care unit (OR for 1 mm Hg increment 1.020, 95% CI 1.006-1.035), while education was protective (OR per year of increment 0.53, 95% CI 0.31-0.90). CONCLUSIONS: A considerable proportion of cardiac surgery patients may undergo clinically relevant cognitive impairment. The knowledge of variables influencing cognitive outcome is essential for the adoption of preventive measures.

Adult↗
PubMed2001

Abulia and cognitive impairment in two patients with capsular genu infarct.

BACKGROUND: An internal capsule genu infarct has been rarely reported to cause cognitive impairment and behavioral changes. This clinical picture can be explained on anatomical and functional basis because important subcortical-cortical pathways traverse the internal capsule genu. We report 2 previously non-demented patients who developed acute confusional state, abulia, and moderate cognitive decline after the occurrence of an infarct in the capsular genu. METHODS: Clinical, neuropsychological, and MRI evaluation at baseline and 12-month follow-up. RESULTS: Abulia and cognitive impairment were still present 1 year after stroke. In 1 patient there were associated multiple lacunar infarcts and leukoaraiosis. In the other an old small left frontal infarct was also present. In both moderate cortical atrophy co-existed. CONCLUSIONS: We hypothesize that co-existing lesions, possibly associated with a sub-clinical reduction of cognitive functions, facilitate the development of a persistent clinically evident mental deficit after the occurrence of an infarct in the capsular genu.

Aged↗
PubMed1999

Growth, cellular differentiation and virulence factor expression by Proteus mirabilis in vitro and in vivo.

A uropathogenic strain of Proteus mirabilis was grown in vitro in human and mouse urine and brain-heart infusion broth (BHIB) and in vivo in subcutaneous open chambers (SOC) in mice, intraperitoneal diffusion chambers (IPC) in rats and by ascending urinary tract infection in mice in order to compare growth pattern, cellular differentiation and expression of virulence factors. Although the growth rate was slower in vivo than in vitro, the extent of growth was similar after 24 h. PR mirabilis differentiated into filamentous swarmer cells in all in-vitro culture conditions, but no filamentous cells were observed in either of the in-vivo chamber models. Transurethrally infected mice showed a rapid release or loss of filamentous cells and these could not be seen in kidney or bladder homogenates 7 days after infection. Bacteria showed increasing haemagglutination titres for fresh and tanned red blood cells after subculturing in BHIB, but bacteria grown in vivo did not show haemagglutination. An increasing resistance to normal serum was found when bacteria were grown in vivo. Significant haemolytic activity was detected with bacteria grown in BHIB and IPC, but almost no activity was found when bacteria had grown in urine. These findings improve the understanding of the role of P. mirabilis uropathogenic virulence factors in vivo.

Animals↗
PubMed1998

Treatable and reversible dementias: an update.

The ever greater emphasis on the application of a standard work-up in the clinical diagnosis of dementia -- and Alzheimer's Disease (AD) in particular -- has made it easier to identify potentially treatable and/or reversible cases. The aim of this paper is to update the issue of treatable and reversible dementias.

Dementia↗
PubMed1998

Alzheimer's disease: patterns of cognitive impairment at different levels of disease severity.

The aim of this study was to establish the presence and the consistency of different cognitive profiles in AD patients taking into consideration the severity of mental impairment. Therefore we stratified 679 neuropsychological observations on 119 probable AD patients followed longitudinally on the basis of overall degree of cognitive impairment. To compare performance on tests with different score ranges we transformed raw test scores into coefficients; to summarize our results in terms of language versus visuo-spatial performance we computed indices of prevalent impairment of performance (IPIP) by subtracting the coefficients for constructional praxis from coefficients for language-related tests. Finally, we converted these indices into z-scores for each level of mental decline to identify patients with generalized, language (L) or visuo-spatial (V) prevalent impairment. The latter, 30% of the sample, can be detected at all stages of dementia. There was a higher percentage of males among language impaired patients (P<0.05). Approximately half of patients with L/V prevalent impairment continued to show such a focality when followed longitudinally. The groups did not differ in the annual rate of cognitive decline.

Age of Onset↗
PubMed1998

Rate of progression of mental decline in Alzheimer disease: summary of European studies.

The aim of this study was to provide an update on the rate of progression in Alzheimer disease. In particular, we conducted a survey on European longitudinal studies that focused on the course of the disease and were performed since 1992. By means of Medline search and review papers and by personal contact with principal investigators, a census of existing studies on natural history of the disease in Europe has been carried out. We present data arising from our search and discuss methodological aspects by comparing data available from U.S. studies on disease progression and implications for clinical trials.

Aged↗
PubMed1997

Modality-specific operations in semantic dementia.

A patient suffering from semantic dementia is described who consistently demonstrated the preserved ability to support specific types of semantic judgements from visual, but not from verbal, input. In addition the representations accessed from visual input were found to trigger complex behavioural schemata, while with verbal materials the patients performed almost invariably at chance level. A preliminary description is given of the nature of visual semantic representations, and the privileged relationship between this modality of input and some aspects of semantic knowledge is also explored. The richness of the semantic representations accessed from visual input can be accommodated within the "Multimodal Semantics" framework; alternative views, derived from the Identification Semantics and the Organized Unitary Content Hypothesis, are also discussed.

Aged↗
PubMed1996

Defined mutants of Proteus mirabilis lacking flagella cause ascending urinary tract infection in mice.

A clinical isolate of Proteus mirabilis (Pr 990) and an isogenic non-flagellate allelic replacement mutant (Pr M9) were tested for their ability to cause infection in the ascending mouse model of urinary tract infection. Wild-type Pr 990 differentiates into swarmer cells in brain-heart infusion broth. Pr M9 neither has flagella nor does it apparently differentiate into swarmer cells after subculturing. The infectivity of both strains from an initial culture and the sixth subculture was assessed in the ascending urinary tract infection mouse model. Infection was ascertained by determining colony forming units from kidney and bladder homogenates from individual mice 7 days after inoculation. In all cases the nonflagellate mutant Pr M9 was at least as infective as Pr 990. Using bacteria from the first culture, Pr M9 infected 61.5% and Pr 990 infected 45.5% of mice tested. The levels of viable counts were similar between the Pr M9 and the Pr 990 infections. Using bacteria from the sixth subculture, Pr M9 infected 75% and Pr 990 infected 76.5% of mice tested. Again viable counts were similar. Pr 990 increased in infectivity from the first to the sixth subculture, whereas Pr M9 did not, but this may be a reflection of the high initial rate of infectivity with first culture Pr M9. These results suggest that neither flagella nor swarmer cells are required for P. mirabilis infectivity in ascending urinary tract infections in mice.

Alleles↗
PubMed1995

Natural history of Alzheimer's disease: prognostic value of plateaux.

The aim of this 7-year inception cohort study was to determine the prognostic value of plateaux in cognitive decline in the course of Alzheimer's disease (AD) as well as their impact on the rate of progression of cognitive impairment. From a consecutive sample of 106 outpatients participating in a longitudinal study on AD, we selected 31 with a mild degree of mental deficit at presentation and a disease duration of at least 3 years when included into the study. All underwent extensive clinico-neuropsychological testing about every 6 months and there were no drop-outs. Mean period of follow-up lasted 6.8 (SD 2.9) years. Nineteen patients displayed a plateau, where a plateau refers to a patient's remaining on a mild level of cognitive decline for more than two years. Survival curves (Kaplan-Meier method) showed that patients with plateaux reached several end-points--very severe functional or cognitive impairment, urinary incontinence, death--significantly later than patients without (p < 0.04). Patients with plateaux showed a smaller cognitive loss (p < 0.01) in terms of the mean annual rate of progression of mental decline. In conclusion plateaux in an early stage of Alzheimer's Disease served to identify patients with a more favourable course.

Aged↗
PubMed1994

Flagellate and non-flagellate Proteus mirabilis in the development of experimental urinary tract infection.

Three isolates of Proteus mirabilis from symptomatic human urinary tract infections (UTI) were tested for their ability to cause renal infection in mice. All three strains were fimbriated as tested by hemagglutination. One of the strains, Pr 988, did not possess flagella, whereas the other two did and were capable of swarming on solid rich media. We compared the capacity of these strains to infect mice in both the ascending and hematogenous mouse UTI models. Infection was assessed by counting viable bacteria in kidney and bladder homogenates in ascending UTI or by the presence of abscesses in the hematogenously inoculated mice. All three strains were able to infect mice in both UTI models. These results suggest that flagella are not absolutely necessary for virulence in these experimental models.

Administration, Intravesical↗
PubMedDate not supplied

Magnetic resonance measures in Alzheimer disease: their utility in early diagnosis and evaluating disease progression.

We sought to identify the most reliable magnetic resonance (MR) measures for the diagnosis and staging of Alzheimer disease (AD) in a clinical setting and to estimate, for different degrees of dementia, the rate of change of cerebral atrophy in certain regions of interest (ROIs). Forty-two probable AD patients and eight normal controls underwent MR brain scans, neurological examinations, and neuropsychological testing. We computed each subject's corpus callosum width, ventricular size, right and left temporal lobe areas, interuncal distance, and assessed the degree of cortical atrophy. We also estimated the rate of change for Information-Memory-Concentration Test scores and for temporal lobe areas and corpus callosum width. Measures of temporal lobe area and subjective evaluation of temporal lobe atrophy both served to distinguish controls from mild AD cases (p < 0.05), whereas only the latter differentiated moderate from severe patients (p < 0.05). The rate of change for temporal lobe areas remained constant over different AD stages, whereas those for corpus callosum width and for cognitive impairment were greater for severe cases (p < 0.05). Our findings imply that measurements of temporal lobe area and ratings of temporoparietal atrophy can be useful in the diagnosis and staging of AD and suggest that atrophy progressed at different rates in selected ROIs for various stages of AD severity.

Aged↗