Your search for: 'author:("Troen, Aron M.")' has returned 3 results. (0.007s) Save search

Authors: Troen, Aron M. | Shukitt-Hale, Barbara | Chao, Wei-Hsun | Albuquerque, Bina | Smith, Donald E. | Selhub, Jacob | Rosenberg, Irwin H.

Article Type: Research Article

Abstract: Homocysteinemia is associated with cognitive dysfunction in the elderly ranging from subtle cognitive decline to dementia. Homocysteine is generated from methionine as a product of biological methylation reactions and is disposed of through reactions that require folate and vitamins B12 and B6. While different disruptions in these reactions can result in homocysteinemia, it is unclear if they will also result in homocysteine-mediated cognitive dysfunction. Young ApoE-deficient mice were fed one of four diets with differing methionine and B-vitamin content for eight weeks, before undergoing psychomotor tests, the Morris Water Maze test of spatial memory and learning, and measurement of home-cage …activity. B-vitamin deficiency induced homocysteinemia and selectively impaired Morris Water Maze performance without affecting other behavioral measures. The cognitive deficits occurred in the absence of overt histologic neurodegeneration but in association with moderate impairments of brain methylation potential. Diets that yielded cognitive deficits were different from those that exacerbated aortic pathology. These findings are inconsistent with a single mechanism linking homocysteinemia to neurological dysfunctions mediated by homocysteine vasotoxicity. Instead, they indicate that different “types” of homocysteinemia, or in other words different impairments of nutritional metabolism affecting homocysteine levels, may lead to different end organ dysfunctions and/or diseases. Show more

Keywords: ApoE, folate, homocysteine, methionine, nutrition, behavior, cognition, model, dementia, neurodegeneration

DOI: 10.3233/JAD-2006-9403

Citation: Journal of Alzheimer's Disease, vol. 9, no. 4, pp. 381-392, 2006

Authors: Shaul, Merav E. | Hallacoglu, Bertan | Sassaroli, Angelo | Shukitt-Hale, Barbara | Fantini, Sergio | Rosenberg, Irwin H. | Troen, Aron M.

Article Type: Research Article

Abstract: Background: Senescent changes in brain microvascular circulation may cause or contribute to age-related cognitive decline. Such changes are promoted partly by aging, but also by chronic hypertension, a leading treatable cause of cognitive decline. Objectives: We aimed to non-invasively detect in vivo the senescent changes in brain microvascular circulation associated with age and hypertension, and inquired whether decrements driven by aging would be exacerbated by chronic hypertension. Methods: In this longitudinal study, absolute near infrared spectroscopy (NIRS) was used to quantify in vivo cerebral blood volume (CBV) and assess the hemodynamic response to a hypercapnic respiratory challenge in normotensive Wistar-Kyoto …(WKY) and spontaneous-hypertensive (SHR) rats. The impact of age and hypertension were evaluated by repeating these measurements on the same animals at 4- and 16-months of age. Results: CBV decreased markedly with age in both strains, from 4.5 ± 0.2 to 2.6 ± 0.1 ml/100g tissue, on average. Chronic hypertension, however, did not significantly exacerbate this age-related decrease in CBV (−48.1 ± 3.7% in WKYs versus −53.3 ± 5.4% in SHRs). In contrast, vasoreactivity was already impaired in the young hypertensive rats (ΔVMR 0.017 ± 0.014 in young SHRs versus 0.042 ± 0.005 in young WKYs) and further worsened by middle-age (ΔVMR 0.011 ± 0.017 middle-aged SHRs). Conclusion: Whereas a decrease in brain blood volume correlated with age but not hypertension, vasodilatory capacity was diminished due to hypertension but did not appear affected by age alone. The ability of absolute NIRS to distinguish between such senescent changes in brain (micro)vascular circulation in life may allow early detection and intervention to preserve cerebrovascular health with age. Show more

Keywords: Aging, cerebral blood volume, hypertension, near infrared spectroscopy, vasodilation

DOI: 10.3233/JAD-132504

Citation: Journal of Alzheimer's Disease, vol. 42, no. s3, pp. S189-S198, 2014

Authors: Lotan, Roni | Ganmore, Ithamar | Livny, Abigail | Itzhaki, Nofar | Waserman, Mark | Shelly, Shahar | Zacharia, Moran | Moshier, Erin | Uribarri, Jaime | Beisswenger, Paul | Cai, Weijing | Troen, Aron M. | Beeri, Michal Schnaider

Article Type: Research Article

Abstract: Background: Dietary advanced glycation end-products (AGEs) are linked to cognitive decline. However, clinical trials have not tested the effect of AGEs on cognition in older adults. Objective: The aim of the current pilot trial was to examine the feasibility of an intervention to reduce dietary AGEs on cognition and on cerebral blood flow (CBF). Methods: The design is a pilot randomized controlled trial of dietary AGEs reduction in older adults with type 2 diabetes. Seventy-five participants were randomized to two arms. The control arm received standard of care (SOC) guidelines for good glycemic control; the intervention arm, in addition to …SOC guidelines, were instructed to reduce their dietary AGEs intake. Global cognition and CBF were assessed at baseline and after 6 months of intervention. Results: At baseline, we found a reverse association between AGEs and cognitive functioning, possibly reflecting the long-term toxicity of AGEs on the brain. There was a significant improvement in global cognition at 6 months in both the intervention and SOC groups which was more prominent in participants with mild cognitive impairment. We also found that at baseline, higher AGEs were associated with increased CBF in the left inferior parietal cortex; however, 6 months of the AGEs lowering intervention did not affect CBF levels, despite lowering AGEs exposure in blood. Conclusion: The current pilot trial focused on the feasibility and methodology of intervening through diet to reduce AGEs in older adults with type 2 diabetes. Our results suggest that participants with mild cognitive impairment may benefit from an intensive dietary intervention. Show more

Keywords: Advanced glycation end products, diet, feasibility, mild cognitive impairment, randomized controlled trial, pilot, type 2 diabetes

DOI: 10.3233/JAD-210131

Citation: Journal of Alzheimer's Disease, vol. 82, no. 4, pp. 1785-1795, 2021