Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel radiotracer shines new light on the brains of Alzheimer's disease patients

25.06.2010
New tool could aid in diagnosing Alzheimer’s, tracking disease progression and developing therapeutics

A trial of a novel radioactive compound readily and safely distinguished the brains of Alzheimer's disease patients from healthy volunteers on brain scans and opens the doors to making such imaging available beyond facilities that can manufacture their own radioactive compounds.

The results, reported by a Johns Hopkins team in the June Journal of Nuclear Medicine, could lead to better ways to distinguish Alzheimer's from other types of dementia, track disease progression and develop new therapeutics to fight the memory-ravaging disease.

Previously, the only way to peer into the brains of Alzheimer's patients was through autopsy or the use of another radioactive compound used in scans, or radiotracer, known as Pittsburgh compound or PIB. PIB is drawn to a protein known as beta-amyloid, which accumulates abnormally in the brains of Alzheimer's patients. However, PIB has a half-life of only 20 minutes, meaning that half of the substance degenerates every 20 minutes after it is made. Consequently, PIB's use is possible only at a few hospitals or academic medical centers with facilities to manufacture it since this compound degenerates so rapidly.

... more about:
»Medicine »brain scans »cognitive tests

To solve this conundrum, Dean F. Wong, M.D., Ph.D., a professor of radiology and psychiatry at the Johns Hopkins University School of Medicine, and his colleagues looked to a new radiotracer known as 18F-AV-45 (also known as florbetapir F18). This compound, based on the radioactive isotope fluorine-18, is drawn to beta-amyloid like PIB. However, unlike PIB, florbetapir has a half-life of about 110 minutes, greatly increasing its ability to be transported significant distances away from manufacturing facilities.

Testing the new compound for the first time in humans, Wong and his colleagues recruited 26 volunteers — 11 previously diagnosed with Alzheimer's disease, and 15 healthy subjects of similar age who performed normally on cognitive tests. Each of these volunteers received an injection of florbetapir, then received a PET scan of their brains. The brain scans, acquired over a 90-minute period, allowed the researchers to see the uptake of florbetapir in the brain over time.

Florbetapir had significantly heavier accumulation in the Alzheimer's patients' brains compared to the healthy volunteers, collecting in brain regions expected to be high in beta-amyloid deposits based on previous research. The results in AD patients were readily distinguishable from those of healthy subjects by 30 minutes after injection, and the differences continued for up to at least 90 minutes after injection of florbetapir. None of the AD patients or healthy volunteers suffered any ill effects from florbetapir and showed normal vital signs, electrocardiograms and blood-work after the scan.

"We could easily tell apart the two groups of patients. Those without Alzheimer's disease retained much less of the compound, and those with Alzheimer's disease retained much more of it," Wong says. "This is the first time we've been able to get results like this with a compound that can travel beyond the confines of a major academic medical center to the majority of the U.S. population."

Wong adds that florbetapir's portability could lead to numerous applications for this compound. For example, though Alzheimer's disease can usually be diagnosed from neurocognitive tests, imaging with florbetapir could help settle tricky cases in which patients might have other forms of dementia instead. The compound may also be useful in future studies designed to help solve current medical mysteries, such as which patients are most likely to progress from mild cognitive impairment to full-blown Alzheimer's disease.

Florbetapir may also be useful in trials of new experimental Alzheimer's therapeutics to measure their success, a purpose for which this compound is already being used on a limited basis, Wong says.

This study was funded in part by Avid Pharmaceuticals, maker of florbetapir, and grants from the National Institutes of Health.

Other Johns Hopkins researchers who participated in this study include Paul B. Rosenberg, M.D., Yun Zhou, Ph.D., Anil Kumar, M.B.B.S., Vanessa Raymont, M.B.Ch.B., M.S., Hayden T. Ravert, Ph.D., Robert F. Dannals, Ph.D., Ayon Nandi, M.S., James R. Brašiæ, M.D., M.P.H., Weiguo Ye, M.D., John Hilton, D.Phil., and Constantine Lyketsos, M.D .

For more information, go to:

http://www.hopkinsradiology.org/Nuclear%20Medicine/Faculty/Wong
http://www.hopkinsradiology.org/Nuclear%20Medicine/Index.html

Christen Brownlee | EurekAlert!
Further information:
http://www.jhmi.edu

Further reports about: Medicine brain scans cognitive tests

More articles from Health and Medicine:

nachricht Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>