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Archive - Jun 16, 2009

Blood Test Detects Marker for Human Aging

Levels of a well-known tumor suppressor protein, p16INK4a, increase sharply with age in most mammalian tissues, and these increases contribute to an age-induced functional decline of certain self-renewing compartments. Researchers at the University of North Carolina have now shown that p16INK4 can be detected in peripheral blood T-lymphocytes (PBTL) and that its expression levels are strongly correlated with an individual's chronological age and, in fact, increase exponentially with age. In addition, increased expression levels of p16INK4a were independently associated with certain behaviors (tobacco use and physical inactivity) known to accelerate human aging. p16INK4a levels were also associated with a biomarker of human frailty. The authors said that the data suggest that p16INK4 expression in PBTL is an easily measured, peripheral blood biomarker of molecular age. "This is a major step toward a practical tool to clinically determine a person's actual molecular, as opposed to just their chronological, age," said Dr. Norman Sharpless, the senior author of the study. "Although we don't know whether this test is a good reflection of cellular age in all types of human tissues, we believe it is a first step toward a better understanding of issues like the suitability of organs for transplantation, how well patients are likely to recover after surgery, or the future toxicity of chemotherapy for cancer patients," he added. This work was published online ahead of pring in Aging Cell. [Press release] [Aging Cell abstract]

Spectroscopy Technology May Detect Early Alzheimer’s

Researchers have shown that the use of near-infrared (NIR) biospectroscopy to detect indicators of changes in oxidative stress levels in blood plasma may be a useful approach to the early identification of Alzheimer’s disease (AD). The procedure is minimally invasive, rapid, and relatively inexpensive. There is currently no accepted laboratory test for diagnosing AD. Diagnosis is based solely on a patient's medical history and neurological examination, is labor-intensive and expensive, and is often inconclusive in early stages of the illness. The availability of a biologic marker (in this case, a chemical signature of indicators of oxidative stress levels) that reliably differentiates AD from normal aging and other dementing conditions would represent a major achievement in the management of this common neurodegenerative disorder. In differentiating AD patients from the normal elderly control group, the NIR biospectroscopy approach achieved a sensitivity of 80% and specificity of 77%. "These results demonstrate the potential for NIR biospectroscopy to differentiate mild, and possibly pre-clinical, Alzheimer's disease from normal aging with high accuracy," said Dr. Hyman Schipper, senior author of the study. "We are very encouraged by these data and look forward to testing this potential diagnostic tool in larger-scale studies." This work was published in the June issue of the Journal of Alzheimer’s Disease. [Press release 1] [Press release 2] [June issue of JAD]

Targeted Nanoparticles May Improve on Whole-Body Chemotherapy

Researchers using nanoparticles with attached molecules of folic acid and containing the widely-used anti-cancer drug taxol have shown that it may be possible to target cancer cells specifically and thus avoid the multiple side effects that are seen with toxic whole-body chemotherapies such as taxol. The specificity is built upon cancer cells’ high consumption of folic acid. In addition to taxol, the nanoparticles contain a fluorescent dye and an iron oxide magnetic core. Thus, the location of the nanoparticles within cells and the body can be detected with optical imaging and magnetic resonance imaging. This allows the physician to see how the tumor is responding to the treatment. The nanoparticles can also be engineered without the drug and used as imaging (contrast) agents for cancer. If there is no cancer, the biodegradable nanoparticles will not bind to the tissue and will be eliminated by the liver. The iron oxide core will be utilized as regular iron in the body. "What's unique about our work is that the nanoparticle has a dual role, as a diagnostic and therapeutic agent, in a biodegradable and biocompatible vehicle," said Dr. J. Manuel Perez, senior author of the report. This research, by scientists at the University of Central Florida and the Memorial Sloan-Kettering Cancer Center, was published in the journal Small. [Press release] [Small abstract]