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Ramadori G.,University of Texas Southwestern Medical Center | Fujikawa T.,University of Texas Southwestern Medical Center | Anderson J.,University of Texas Southwestern Medical Center | Berglund E.D.,University of Texas Southwestern Medical Center | And 8 more authors.
Cell Metabolism | Year: 2011

Chronic feeding on high-calorie diets causes obesity and type 2 diabetes mellitus (T2DM), illnesses that affect hundreds of millions. Thus, understanding the pathways protecting against diet-induced metabolic imbalance is of paramount medical importance. Here, we show that mice lacking SIRT1 in steroidogenic factor 1 (SF1) neurons are hypersensitive to dietary obesity owing to maladaptive energy expenditure. Also, mutant mice have increased susceptibility to developing dietary T2DM due to insulin resistance in skeletal muscle. Mechanistically, these aberrations arise, in part, from impaired metabolic actions of the neuropeptide orexin-A and the hormone leptin. Conversely, mice overexpressing SIRT1 in SF1 neurons are more resistant to diet-induced obesity and insulin resistance due to increased energy expenditure and enhanced skeletal muscle insulin sensitivity. Our results unveil important protective roles of SIRT1 in SF1 neurons against dietary metabolic imbalance. © 2011 Elsevier Inc. Source


Gutierrez-Robledo L.M.,Institute Geriatria
European Geriatric Medicine | Year: 2012

Sarcopenia is an increasingly recognized problem in the elderly. Recently an algorithm to detect this condition was developed. The aim of our study was to determine the prevalence of sarcopenia in a group of elderly in Mexico City, using the European Wording Group on Sarcopenia in Older People (EWGSOP) algorithm. A cross-sectional assessment of community dwelling elderly was performed in a sample of 345 subjects, who were 70 years or older, during the year of 2008. The data was gathered by a group of standardized interviewers. In order to determine sarcopenia, muscle mass, muscle strength and physical performance were obtained from database. Muscle mass was measured by means of calf circumference, muscle strength by grip strength and physical performance by gait speed. Cut-points suggested in the EWGSOP algorithm of sarcopenia detection (ASD) were used. A total number of 116 (33.6%) subjects were detected as sarcopenic, 75 (48.5%) women and 41 (27.4%) men; with a greater prevalence in 80-year or older subjects (50.4%). Sarcopenic obesity was found in five subjects (1.4%), moderate sarcopenia in 21 subjects (6%) and severe sarcopenia in 94 subjects (27.2%). The ASD of the EWGSOP is a useful tool for detecting sarcopenia prevalence; the frequency in our population was similar to other reports using other methodology. © 2012 Published by Elsevier Masson SAS. Source


Quiroz-Baez R.,National Autonomous University of Mexico | Quiroz-Baez R.,Institute Geriatria | Flores-Dominguez D.,National Autonomous University of Mexico | Arias C.,National Autonomous University of Mexico
Current Alzheimer Research | Year: 2013

Synaptic loss is the major neuropathological correlate of memory decline as a result of Alzheimer's Disease (AD). Synaptic failure appears to depend on the toxic actions of small and soluble amyloid-β (Aβ) oligomers. However, few studies have addressed the mechanism by which aging makes synapses more vulnerable to Aβ toxicity. In the present study we analyzed mitochondrial function and morphology and markers of oxidative stress in isolated presynaptic nerve endings from the hippocampus that were exposed to Aβ peptide at different ages. We found an age-related decline in mitochondrial activity, reduced antioxidant contents and increased oxidative stress markers in resting and depolarized synaptic terminals. Ultrastructural changes including an increase in mitochondrial size and a significant reduction of synaptic vesicles contents were also observed. In addition, synaptosomes obtained from 24 month old rats were more sensitive to Aβ toxicity. These data provide evidence of morphological and biochemical synaptic changes associated with aging that may contribute to exacerbate the damaging effects of Aβ. © 2013 Bentham Science Publishers. Source


Mejia-Arango S.,Colegio de Mexico | Gutierrez L.M.,Institute Geriatria
Journal of Aging and Health | Year: 2011

Objective: To estimate the prevalence and incidence of dementia and cognitive impairment without dementia (CIND) in the Mexican population. Method: The MHAS study is a prospective panel study of health and aging in Mexico with 7,000 elders that represent eight million participants nationally. Using measurements of cognition and activities of daily living of dementia cases and CIND were identified at baseline and follow-up. Overall incidence rates and specific rates for sex, age, and education were calculated. Results: Prevalence was 6.1% and 28.7% for dementia and CIND, respectively. Incidence rates were 27.3 per 1,000 person-years for dementia and 223 per 1,000 persons-year for CIND. Rates of dementia and CIND increased with advancing age and decreased with higher educational level; sex had a differential effect depending on the age strata. Hypertension, diabetes, and depression were risk factors for dementia but not for CIND. Discussion: These data provide estimates of prevalence and incidence of dementia and cognitive impairment in the Mexican population for projection of future burden. © 2011 SAGE Publications. Source


Castrejon-Perez R.C.,National Autonomous University of Mexico | Castrejon-Perez R.C.,Institute Geriatria | Borges-Yanez S.A.,National Autonomous University of Mexico
Gerodontology | Year: 2012

Background and Objective: The Oral Health Impact Profile is the most frequently used and validated of the Oral Health Quality of Life instruments. Several short versions have been developed; and a validation of the OHIP-49 in Spanish has been published. The objective was to develop the short version of the Oral Health Impact Profile in Spanish (OHIP-EE-14). Methods: Cross-sectional study. One hundred and thirty-one persons aged ≥60 years attending a social centre for the elderly, residents of a nursing home and persons seeking dental care at a dental school in Mexico City were interviewed and examined. The validity of each of the 49 questions was evaluated, and, to construct the short version, 14 items were selected. The perceived need for dental treatment, number of teeth, presence of coronal caries, root caries, presence of dental plaque and utilisation of removable prosthesis were measured. Internal consistency, repeatability and discriminant validity were calculated. Results: The OHIP-EE-14 was reliable (Cronbach's-α = 0.918, ICC = 0.825). Significant associations were found between OHIP-EE-14 and the number of teeth and perceived need for dental treatment. Conclusions: The OHIP-EE-14 is a reliable and valid instrument and can be used in subjects aged 60 years and over from Mexico City. © 2012 The Gerodontology Society and John Wiley & Sons A/S. Source

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