Hector Valenzuela

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Telomeres, the repeated sequences that cap chromosome ends, undergo shortening with each cell division, and therefore serve as markers of a cell's replicative history. In vivo, clonal expansion of T cells during immune responses to both foreign and autoantigens is associated with telomere shortening. To investigate possible immune alterations in Alzheimer's(More)
Immune cells are eminently suitable model systems in which to address the possible role of replicative senescence during in vivo aging. Since there are more than 10(8) unique antigen specificities present within the total T lymphocyte population of each individual, the immune response to any single antigen requires massive clonal expansion of the small(More)
Telomeres are structures at the ends of chromosomes that shorten during cell division and eventually signal an irreversible state of growth arrest known as cellular senescence. To delay this cellular aging, human T cells, which are critical in the immune control over infections and cancer, activate the enzyme telomerase, which binds and extends the(More)
False autoregulation has been described as an alteration of autoregulation in which the apparent maintenance of a constant cerebral blood flow (CBF) when increasing cerebral perfusion pressure (CPP) is due to an increase in brain tissue pressure. The objective of our study was to investigate how often false autoregulation occurred in patients with a severe(More)
Considerable controversy continues to exist in scientific and policy circles about how to tackle issues of global hunger, malnutrition, and rural economic decline, as well as environmental issues, such as biodiversity loss and climate change adaptation. On the one hand, powerful vested interests, with close ties to government, media, and academic(More)
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