Biomedical subjects
Publications and source records attributed to C Piccini.
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.
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.
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.
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.
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.
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.
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.