Applicability of the CERAD neuropsychological battery to Brazilian elderly.

There is a limited choice of psychometric tests for Portuguese speaking people which have been evaluated in well defined groups. A Portuguese version of CERAD neuropsychological battery was applied to a control group of healthy elderly (CG) (mean age 75.1 years/ education 7.9 years), 31 Alzheimer disease (AD) patients classified by clinical dementia rating (CDR) as CDR1 (71.4/ 9.0) and 12 AD patients CDR 2 (74.1/ 9.3). Cut-off points were: verbal fluency-11; modified Boston naming-12; Mini-mental State Examination (MMSE) -26; word list memory-13; constructional praxis-9; word recall-3, word recognition-7; praxis recall-4. There was a significant difference between CG and AD-CDR1 (p<0.0001) for all tests. There was a less significant difference for constructional praxis and no difference for Boston naming. Comparison between AD-CDR1 and AD-CDR2 showed difference only for MMSE, verbal fluency, and Boston naming. The performance of CG was similar to that of a US control sample with comparable education level. These results indicate that this adaptation may be useful for the diagnosis of mild dementia but further studies are needed to define cut-offs for illiterates/low education people.

Alzheimer's disease and ageing: a chromosomal approach.

Alzheimer's disease (AD) is the most common type of dementia in elderly people. Interrelations between AD and senescence have been the subject of many studies. Some researchers have suggested that chromosomal alterations may be involved in the etiology or pathogenesis of AD. We present cytogenetic findings in patients with Alzheimer's disease, normal elderly controls and young controls. Aneuploidy, premature centromere division, polyploidy and C-anaphase, were analysed and the results suggest that the cytogenetic alterations observed are inherent to the cellular ageing process and not specifically related to Alzheimer's disease.

Fragile sites, Alzheimer's disease, and aging.

The fragile site expression under conditions of folate deprivation was compared in the chromosomes from 5 Alzheimer's disease (AD) female patients, 5 healthy elderly females and 5 healthy young females. Although different fragile sites were observed in the three groups, nevertheless, more similarities were found between the AD patients and elderly normal donors. The only fragile site common to all groups was 3p14. This site was the most frequent in the young donors group. In both AD and elderly control groups we observed a higher frequency of fragility in 6p21, but not in the young controls. Other interesting fragility points observed in these two groups were: 6q21 and 14q24 (in the AD patients) and 9q13, 14q24 and 17q21 (in the healthy aged). 6p21 and 17q21 have been proposed as 'new' fragile sites. We confirm the existence of these fragile sites and comment that in these bands the genes MTBT2 and MTBT1, which are microtubule (beta) associated protein tau-like and tau 1, respectively, are mapped. The tau protein is a component of paired helical filaments which accumulate in degenerating neurons in the brain of patients with AD and with less intensity of normal elderly individuals.

Lymphocyte proliferation and sister chromatid exchange in Alzheimer's disease.

Sister chromatid exchange (SCE) and lymphocyte proliferation were studied in peripheral lymphocyte cultures derived from 5 patients with Alzheimer disease (AD), 5 control elderly subjects and 5 young donors. These parameters did not differ significantly between the AD group and the elderly control group, but higher SCE frequency and less intensive proliferation were observed in the AD group and in the elderly control group when compared to the young donors.

Investigation of the effect of hydrogen peroxide on the chromosomes of young and elderly individuals.

Active oxygen species have been considered to be responsible for the aging process and for the induction and initiation of neoplastic processes. The effect of hydrogen peroxide, an active oxygen species, was investigated in the chromosomes of three young women (20-21 years of age) and of three elderly women (73-79 years of age) in a culture medium favorable to the appearance of folate-sensitive fragile sites. Hydrogen peroxide at a final concentration of 5 X 10(-6) during the final hours of culture caused a significant increase in hypodiploidy and structural aberrations, chromatid gaps in particular, only in the cultures from the three elderly women, suggesting that the chromosomes of older women are more sensitive to this agent than those of younger women. The preferential chromosome loss in both treated and untreated cultures from the elderly women involved chromosome X. The preferential sites for structural aberrations were 9p12, a constitutive heterochromatin site and 6q21, where the gene of mitochondrial superoxide dismutase, an enzyme involved in antioxidant processes in the cell, is located. Hydrogen peroxide significantly intensified the effect naturally occurring in the cells of elderly persons, such as hypodiploidy and increased structural aberrations, thus acting at the chromosome level in a manner similar to that of the natural aging process of the organism.