Posts Tagged ‘biomarker’

Bio-Rad News: New biomarker could reveal Alzheimer’s disease years before onset

 :: Posted by American Biotechnologist on 08-14-2013

A study published today reported the identification of what may be the earliest known biomarker associated with the risk of developing Alzheimer’s disease (AD). The results suggest that this novel potential biomarker is present in cerebral spinal fluid (CSF) at least a decade before signs of dementia manifest.

“If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer’s disease,” said Dr. Ramon Trullas, research professor at the CSIC Institute of Biomedical Research of Barcelona and lead author of the study that was published in Annals of Neurology. “This discovery may enable us to search for more effective treatments that can be administered during the preclinical stage.”

Difficult Diagnosis

Alzheimer’s disease affects more than five million Americans and is the sixth leading cause of death in the United States. At present, the only way to accurately diagnose the disease is by post-mortem neuropathological analysis. The relationship of currently known biomarkers with the cause of the disease is unclear, making it nearly impossible to diagnose preclinical stages of the disease with any real certainty.

The CSIC researchers demonstrated that a decrease in the content of mitochondrial DNA (mtDNA) in CSF may be a preclinical indicator for Alzheimer’s disease; furthermore, there may be a directly causative relationship. The hypothesis is that decreased mtDNA levels in CSF reflect the diminished ability of mitochondria to power the brain’s neurons, triggering their death. The decrease in the concentration of mtDNA precedes the appearance of well-known biochemical Alzheimer’s biomarkers (the Aβ1-42, t-tau, and p-tau proteins), suggesting that the pathophysiological process of Alzheimer’s disease starts earlier than previously thought and that mtDNA depletion may be one of the earliest predictors for the disease.

In addition to enabling an investigation of the potential causal relationship of mtDNA and Alzheimer’s progression, the use of mtDNA as an index of preclinical Alzheimer’s disease provides an important advantage over previous biochemical markers: the detection of this novel nucleic acid biomarker is unhampered by the technical difficulties associated with protein detection. mtDNA can be readily quantified by real-time quantitative PCR (qPCR) or droplet digital PCR (ddPCR).

Quantitation of mtDNA

Prior to this study, researchers had not reported that circulating cell-free mtDNA could be detected in human CSF. But with this study, Dr. Trullas’ team was able to both detect and reproducibly quantitate mtDNA using qPCR, carefully optimized by adhering to the MIQE guidelines.

To validate their qPCR findings, Dr. Trullas’ team used Bio-Rad Laboratories’ QX100™ Droplet Digital™ PCR system. Unlike qPCR assays, the QX100 system provides an absolute quantification of target DNA molecules without the need for a standard curve. In addition, an important factor for their CSF analysis was that the Droplet Digital PCR system did not require sample purification to remove PCR inhibitors, as is necessary for qPCR assays.

“Droplet Digital PCR allowed us to validate our initial qPCR measurements because it provides absolute quantitation at the single-molecule level without relying on a standard curve,” said Dr. Trullas. “As the technology becomes more widely adopted, we anticipate that Droplet Digital PCR will be the future of detecting mtDNA in cerebral spinal fluid.”

Dr. Trullas hopes that other laboratories and hospitals will successfully replicate his group’s research results, confirming that reduced mtDNA levels should be investigated as a possible cause of Alzheimer’s disease. By finding a way to block this degeneration, clinicians may be able to diagnose and treat Alzheimer’s disease before symptoms appear.

Math Trumps Science in Diagnosing Parkinson’s Disease

 :: Posted by American Biotechnologist on 08-07-2012

Although there are no existing biomarkers for Parkinson’s, diagnosis may just be a phone call away.

New Molecular Tool for Prognosis and Treatment of Brain Tumors

 :: Posted by American Biotechnologist on 01-17-2012

In a paper recently published in BMC Medical Genomics, scientists from Sandra L Rodriguez-Zas’ lab at the University of Illinois have identified a cohort of biomarkers that help predict survivability of patients who are afflicted with the aggressive malignant Glioblastoma multiforme brain tumor. The study also found that survivability varies between different genetic profiles and that factors such as race, gender and therapy may have a significant impact upon the survival and quality of life of individuals afflicted by glioblastoma multiforme.
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Efficient Electrophoresis and Protein Blotting: Aiding Advances in Cardiomyopathy Research

 :: Posted by American Biotechnologist on 11-17-2011

A native of Trinidad and Tobago, Dr Aldrin Gomes decided to specialize in the biochemical differences between normal and diseased hearts in his graduate studies at the University of the West Indies. A significant portion of his research utilized protein separation and purification techniques, making SDS-PAGE electrophoresis and protein blotting an essential tool in most of his experiments. But in a country where resources are scarce, unrelenting heat is destructive to sensitive biological materials, and slow delivery times are common for product orders, Gomes and his colleagues began to analyze the electrophoretic workflow to determine how to make the process as efficient as possible. “Because we performed a lot of electrophoresis, we published some articles whereby we looked at how we could standardize things to improve resolution in our results,” says Gomes. “We heavily researched aliquoting methods, sample buffers (methods for making them and determining actual shelf lives), whether or not buffers can be reused — even minor factors such as gel pouring techniques and plate thickness.”

Since Gomes “grew up,” scientifically speaking, in an environment where experiments must be planned far in advance and resources cannot be wasted, he cultivated the habit of designing experiments and procedures that made the best possible use of tools and time while ensuring optimal results. This followed him through his graduate work and his subsequent career, first as a research associate, then in his current role as assistant professor in the Neurobiology, Physiology and Behavior department in the College of Biological Sciences, and Physiology and Membrane Biology department in the School of Medicine at UC Davis.

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Great talk expalining today’s hot news of new uses for old drugs

 :: Posted by American Biotechnologist on 08-18-2011

For the first time ever, scientists are using computers and genomic information to predict new uses for existing medicines.

A National Institutes of Health-funded computational study analyzed genomic and drug data to predict new uses for medicines that are already on the market. A team led by Atul J. Butte, M.D., Ph.D., of Stanford University, Palo Alto, Calif., reports its results in two articles in the Aug. 17 online issue of Science Translational Medicine.

Butte’s group focused on 100 diseases and 164 drugs. They created a computer program to search through the thousands of possible drug-disease combinations to find drugs and diseases whose gene expression patterns essentially cancelled each other out. For example, if a disease increased the activity of certain genes, the program tried to match it with one or more drugs that decreased the activity of those genes.

Below is a talk that Dr. Buttes gave recently at Packard Children’s Hospital where he explained some of the amazing work done in his lab.

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