Saturday, June 19, 2010

The arsenic exposure hypothesis for Alzheimer disease

Alzheimer Disease and Associated Disorders, 2010 May 13 [Epub ahead of print].
Gong G, O'Bryant SE 
F. Marie Hall Institute for Rural and Community Health Department of Neurology, Texas Tech University Health Sciences Center, Lubbock, TX.
Abstract - Prior research has shown that arsenic exposure induces changes that coincide with most of the developmental, biochemical, pathologic, and clinical features of Alzheimer disease (AD) and associated disorders. On the basis of this literature, we propose the Arsenic Exposure Hypothesis for AD that is inclusive of and cooperative with the existing hypotheses. Arsenic toxicity induces hyperphosphorylation of protein tau and overtranscription of the amyloid precursor protein, which are involved in the formation of neurofibrillary tangles and brain amyloid plaques, consistent with the amyloid hypothesis of AD. Arsenic exposure has been associated with cardiovascular diseases and associated risk factors, which is in agreement with the vascular hypothesis of AD. Arsenic exposure invokes brain inflammatory responses, which resonates with the inflammatory hypotheses of AD. Arsenic exposure has been linked to reduced memory and intellectual abilities in children and adolescents, which provides a biologic basis for the developmental origin of health and disease hypothesis for AD. Arsenic and its metabolites generate free radicals causing oxidative stress and neuronal death, which fits the existing oxidative stress hypothesis. Taken together, the arsenic exposure hypothesis for AD provides a parsimonious testable hypothesis for the development and progression of this devastating disease at least for some subsets of individuals.

Tuesday, June 8, 2010

Thrifty gene

Thrifty gene provides for survival

Source: Excegen Genetica SA, June 2010

Under dietary restriction, bovines carrying a wild type of the growth hormone gene (GH) are able to sustain body growth, whereas bovines carrying the domestic form of the gene stop growing, according to a study published in the journal Genetics and Molecular Research (GMR).

Sunday, June 6, 2010

MIMER Notes, June 6, 2010: Global map of arsenic in groundwater

Modeled global probability of geogenic arsenic contamination in groundwater for (a) reducing groundwater conditions, and (b) high-pH/oxidizing conditions where arsenic is soluble in its oxidized state. (FIGURE 2 from Amini et al., 2008). Copyright American Chemical Society. Material published under license agreement.

Ref.: Amini M., K.C. Abbaspour, M. Berg, L. Winkel, S. J. Hug, E. Hoehn, H. Yang, C.A Johnson (2008) Preliminary Statistical Modeling of Global Geogenic Arsenic Contamination in Groundwater. Environmental Science & Technology 42:3669-3675.