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Down's syndrome (DS) is the most frequent chromosomal aberration in men. Moreover IDS is considered an atheroma-free model. Plasma levels of interleukin-6 (IL-6), tumor necrosis factor-a high sensitivity (hsTNF-alpha), leptin and adiponectin from non-demented DS subjects of three different age cohorts (2-14, 20-50 and above 60 years) and healthy controls were measured. No clinical and sub-clinical inflammation was apparent in DS patients. Plasma levels of hsTNIF-alpha, IL-6 and leptin were higher in children than in adult and old DS subjects. instead, serum levels of adiponectin were increased in older IDS patients than in DS children and adults. High levels of circulating adiponectin might protect DS from clinical complications of atherosclerosis. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

A link between cholesterol and Alzheimer's disease (AD) had been suggested. Hydroxy-methylglutaryl-coenzyme A reductase (HMGCR) is the rate limiting enzyme in the synthesis of cholesterol. A single nucleotide polymorphism (SNP) in the promoter of this gene, never described in Italian AD population, was investigated in case-control studies. Genotype distribution and allele frequency in two groups of AD patients and non demented controls were investigated. A cohort of AD patients were also followed up for 2 years, cognitive performances recorded and a possible influence of this SNP on the disease progression was tested. The CC genotype of the HMGCR gene was associated with a reduced risk of AD. Conversely the A allele of this polymorphism was over represented in AD patients. The presence of the A allele was also associated with an accelerated cognitive deterioration in AD patients followed up for 2 years. However, transfection experiments showed that this polymorphism did not directly influence functional activity in luciferase reporter gene assays. This polymorphism of the HMGCR gene appears to be linked to both AD risk and disease progression. Present findings reinforce the notion that abnormal regulation of cholesterol metabolism is a key factor in the pathogenesis of the disease.

Background: In cross-sectional studies, elevated plasma total homocysteine (tHcy) concentrations have been associated with cognitiveimpairmentanddementia.Incidencestudiesofthisissuearefew and have produced conflicting results. Objective: We investigated the relation between high plasma tHcy concentrations and risk of dementia and Alzheimer disease (AD) in an elderly population. Design: A dementia-free cohort of 816 subjects (434 women and 382 men; mean age: 74 y) from an Italian population-based study constituted our study sample. The relation of baseline plasma tHcy to the risk of newly diagnosed dementia and AD on follow-up was examined. A proportional hazards regression model was used to adjust for age, sex, education, apolipoprotein E genotype, vascular risk factors, and serum concentrations of folate and vitamin B-12. Results: Over an average follow-up of 4 y, dementia developed in 112 subjects, including 70 who received a diagnosis of AD. In the subjects with hyperhomocysteinemia (plasma tHcy 15 mol/L), the hazard ratio for dementia was 2.08 (95% CI: 1.31, 3.30; P 0.002). The corresponding hazard ratio for AD was 2.11 (95% CI: 1.19, 3.76; P 0.011). Independently of hyperhomocysteinemia and other confounders, low folate concentrations (11.8 nmol/L) were also associated with an increased risk of both dementia (1.87; 95% CI: 1.21, 2.89; P 0.005) and AD (1.98; 95% CI: 1.15, 3.40; P 0.014), whereas the association was not significant for vitamin B-12.

Increased levels of alpha-1-antichymotrypsin (ACT), a protease inhibitor and an acute phase protein, have been found in the brain and peripheral blood of patients with Alzheimer's disease (AD). Patients from northern Italy with a clinical diagnosis of probable AD, and patients with early onset AD (EOAD) from UK with AD neuropathological diagnosis were genotyped for a new polymorphism in the promoter region of the ACT gene which has been shown to affect ACT expression. A subset of patients with clinical AD from northern Italy was also followed up for 2 years and monitored for cognitive decline. The ACT TT promoter genotype was associated with an increased risk of EOAD independently from the presence of the apolipoprotein E (APOE) epsilon 4 allele. After manifestation of the disease the ACT TT genotype was also associated with faster cognitive decline in patients with the APOE allele epsilon 4. The ACT gene appears to influence the early clinical development of the disease, and the interaction of the ACT and APOE genes affects clinical progression of AD.