MAURICIO WAJNGARTEN
Projetos de Pesquisa
Unidades Organizacionais
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Cardiovascular risk in cognitively preserved elderlies is associated with glucose hypometabolism in the posterior cingulate cortex and precuneus regardless of brain atrophy and apolipoprotein gene variations(2013) TAMASHIRO-DURAN, Jaqueline Hatsuko; SQUARZONI, Paula; DURAN, Fabio Luis de Souza; CURIATI, Pedro Kallas; VALLADA, Homero Pinto; BUCHPIGUEL, Carlos Alberto; LOTUFO, Paulo Andrade; WAJNGARTEN, Mauricio; MENEZES, Paulo Rossi; SCAZUFCA, Marcia; ALVES, Tania Correa de Toledo Ferraz; BUSATTO, Geraldo FilhoCardiovascular risk factors (CVRF) possibly contribute to the emergence of Alzheimer's disease (AD). Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been widely used to demonstrate specific patterns of reduced cerebral metabolic rates of glucose (CMRgl) in subjects with AD and in non-demented carriers of the apolipoprotein epsilon 4 (APOE epsilon 4) allele, the major genetic risk factor for AD. However, functional neuroimaging studies investigating the impact of CVRF on cerebral metabolism have been scarce to date. The present FDG-PET study investigated 59 cognitively preserved elderlies divided into three groups according to their cardiovascular risk based on the Framingham 10-year risk Coronary Heart Disease Risk Profile (low-, medium-, and high-risk) to examine whether different levels of CVRF would be associated with reduced CMRgl, involving the same brain regions affected in early stages of AD. Functional imaging data were corrected for partial volume effects to avoid confounding effects due to regional brain atrophy, and all analyses included the presence of the APOE epsilon 4 allele as a confounding covariate. Significant cerebral metabolism reductions were detected in the high-risk group when compared to the low-risk group in the left precuneus and posterior cingulate gyrus. This suggests that findings of brain hypometabolism similar to those seen in subjects with AD can be detected in association with the severity of cardiovascular risk in cognitively preserved individuals. Thus, a greater knowledge about how such factors influence brain functioning in healthy subjects over time may provide important insigths for the future development of strategies aimed at delaying or preventing the vascular-related triggering of pathologic brain changes in the AD.
- Endothelial Alterations in Aging(2018) WAJNGARTEN, M.; NUSSBACHER, A.; DOURADO, P. M. M.; CHAGAS, A. C. P.Age is an important modifying factor of endothelial structure and function in humans. Mechanisms involved in the reduction of age-related endothelium-dependent vasodilation are caused mainly by a primary alteration in the l-arginine-NO pathway. Oxidative stress in the arterial wall plays an important role in the elderly, as it compromises NO bioavailability. The compromise of endothelium-dependent vasodilation in hypertension appears to represent an acceleration of the changes seen in aging. Endothelial dysfunction contributes to making vascular aging a strong risk factor for the development of cardiovascular diseases. On the other hand, experimental evidence suggests that dietary restriction stimulates preservation of vascular function through several mechanisms such as sirtuins, AMP kinase, insulin/insulin-like growth factor 1, and TOR kinase protein. However, controversies still remain as to how caloric restriction improves mitochondrial performance and whether this is sufficient to delay cell and age-dependent decline of the organism. © 2018 Elsevier Inc. All rights reserved.
- Simultaneous transfer of cholesterol, triglycerides, and phospholipids to high-density lipoprotein in aging subjects with or without coronary artery disease(2011) AZEVEDO, Carolina H. M.; WAJNGARTEN, Mauricio; PRETE, Ana C. Lo; DIAMENT, Jayme; MARANHAO, Raul C.OBJECTIVE: To verify whether the capacity of high-density lipoprotein (HDL) to simultaneously receive non-esterified cholesterol, triglycerides, cholesteryl esters, and phospholipids changes with aging and the presence of coronary artery disease. DESIGN: Cross-sectional study with biochemical analyses. SUBJECTS: Eleven elderly patients with coronary artery disease (74 +/- 5 years) were compared with the following groups of non-coronary artery disease subjects (referred to as ""healthy""): 25 young (25 +/- 5 years), 25 middle-aged (42 +/- 6 years), and 25 elderly subjects (75 +/- 8 years). METHODS: Plasma samples were incubated with a nanoemulsion labeled with radioactive lipids; the transfer of the lipids from the nanoemulsion to the HDL was measured in chemically precipitated HDL. HDL size and paraoxonase-1 activity were also determined. RESULTS: The transfer of cholesteryl esters and phospholipids to high-density lipoprotein was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. Non-esterified cholesterol and triglyceride transfer was not different among these three groups. The HDL size was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. The paraoxonase-1 activity was similar among the groups. Compared with healthy elderly subjects, coronary artery disease elderly subjects had significantly less (p<0.05) transfer of non-esterified cholesterol, triglycerides, and cholesteryl esters to the HDL and a significantly smaller (p<0.05) HDL size. CONCLUSION: Because lipid transfer is enhanced in healthy elderly subjects but not in those with coronary artery disease, increasing lipid transfer to HDL may be a protective mechanism against the disease.