Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earlier detection of bone loss may be in future

29.05.2012
Are your bones getting stronger or weaker? Right now, it's hard to know.

Scientists at Arizona State University and NASA are taking on this medical challenge by developing and applying a technique that originated in the Earth sciences. In a new study, this technique was more sensitive in detecting bone loss than the X-ray method used today, with less risk to patients. Eventually, it may find use in clinical settings, and could pave the way for additional innovative biosignatures to detect disease.

"Osteoporosis, a disease in which bones grow weaker, threatens more than half of Americans over age 50," explained Ariel Anbar, a professor in ASU's Department of Chemistry and Biochemistry and the School of Earth and Space Exploration, and senior author of the study.

"Bone loss also occurs in a number of cancers in their advanced stages. By the time these changes can be detected by X-rays, as a loss of bone density, significant damage has already occurred," Anbar said. "Also, X-rays aren't risk-free. We think there might be a better way."

With the new technique, bone loss is detected by carefully analyzing the isotopes of the chemical element calcium that are naturally present in urine. Isotopes are atoms of an element that differ in their masses. Patients do not need to ingest any artificial tracers and are not exposed to any radiation, so there is virtually no risk, the authors noted.

The findings are presented in a paper published in the online Early Edition of the Proceedings of the National Academy of Sciences (PNAS) the week of May 28. It is titled "Rapidly assessing changes in bone mineral balance using natural stable calcium isotopes."

"The paper suggests an exciting new approach to the problem," said Dr. Rafael Fonseca, chair of the Department of Medicine at the Mayo Clinic in Arizona, and a specialist in the bone-destroying disease multiple myeloma. Fonseca was not associated with the study but is partnering with the ASU team on collaborative research based on the findings.

"Right now, pain is usually the first indication that cancer is affecting bones. If we could detect it earlier by an analysis of urine or blood in high-risk patients, it could significantly improve their care," Fonseca said.

The new technique makes use of a fact well known to Earth scientists, but seldom used in biomedicine: Different isotopes of a chemical element can react at slightly different rates. When bones form, the lighter isotopes of calcium enter bone a little faster than the heavier isotopes. That difference, called "isotope fractionation," is the key.

"Instead of isotopes of calcium, think about jelly beans," explained Jennifer Morgan, lead author of the study. "We all have our favorite. Imagine a huge pile of jelly beans with equal amounts of six different kinds. You get to make your own personal pile, picking out the ones you want. Maybe you pick two black ones for every one of another color because you really like licorice. It's easy to see that your pile will wind up with more black jelly beans than any other color. Therefore, the ratio of black to red or black to green will be higher in your pile than in the big one. That's similar to what happens with calcium isotopes when bones form. Bone favors lighter calcium isotopes and picks them over the heavier ones."

Other factors, especially bone destruction, also come into play, making the human body more complicated than the jelly bean analogy. But 15 years ago, corresponding author Joseph Skulan, now an adjunct professor at ASU, combined all the factors into a mathematical model that predicted that calcium isotope ratios in blood and urine should be extremely sensitive to bone mineral balance.

"Bone is continuously being formed and destroyed," Skulan explained. "In healthy, active humans, these processes are in balance. But if a disease throws the balance off then you ought to see a shift in the calcium isotope ratios."

The predicted effect on calcium isotopes is very small, but can be measured using sensitive mass spectrometry methods developed by Morgan as part of her doctoral work with Anbar, Skulan and co-author Gwyneth Gordon, an associate research scientist in the W.M. Keck Foundation Laboratory for Environmental Biogeochemistry at ASU. Co-author Stephen Romaniello, currently a doctoral student with Anbar at ASU, contributed an updated mathematical model.

The new study, funded by NASA, examined calcium isotopes in the urine of a dozen healthy subjects confined to bed ("bed rest") for 30 days at the University of Texas Medical Branch at Galveston's Institute for Translational Sciences–Clinical Research Center. Whenever a person lies down, the weight-bearing bones of the body, such as those in the spine and leg, are relieved of their burden, a condition known as "skeletal unloading". With skeletal unloading, bones start to deteriorate due to increased destruction. Extended periods of bed rest induce bone loss similar to that experienced by osteoporosis patients, and astronauts.

"NASA conducts these studies because astronauts in microgravity experience skeletal unloading and suffer bone loss," said co-author Scott M. Smith, NASA nutritionist. "It's one of the major problems in human spaceflight, and we need to find better ways to monitor and counteract it. But the methods used to detect the effects of skeletal unloading in astronauts are also relevant to general medicine."

Lab analysis of the subjects' urine samples at ASU revealed that the new technique can detect bone loss after as little as one week of bed rest, long before changes in bone density are detectable by the conventional approach, dual-energy X-ray absorptiometry (DEXA).

Importantly, it is the only method, other than DEXA, that directly measures net bone loss.

"What we really want to know is whether the amount of bone in the body is increasing or decreasing", said Morgan.

Calcium isotope measurements seem poised to assume an important role in detecting bone disease – in space, and on Earth. The team is working now to evaluate the technique in samples from cancer patients.

"This is a 'proof-of-concept' paper," explained Anbar "We showed that the concept works as expected in healthy people in a well-defined experiment. The next step is to see if it works as expected in patients with bone-altering diseases. That would open the door to clinical applications."

However, the concept extends even beyond bone and calcium, the authors noted. Many diseases may cause subtle changes in element isotope abundances, or in the concentrations of elements. These sorts of signatures have not been systematically explored in the development of biosignatures of cancers and other diseases.

"The concept of inorganic signatures represents a new and exciting approach to diagnosing, treating and monitoring complex diseases such as cancer," stated Anna Barker, director of Transformative Healthcare Networks and co-director of the Complex Adaptive Systems Initiative in the Office of Knowledge Enterprise Development at ASU. Barker, who came to ASU after being deputy director of the National Cancer Institute, emphasized the simplicity of the approach compared to the challenges of deciphering complex genome-derived data, adding "there is an opportunity to create an entirely new generation of diagnostics for cancer and other diseases."

The National Aeronautics and Space Administration Human Research Program and specifically the Human Health and Countermeasures Element and the Flight Analogs Project supported this work. Bed rest studies were supported in part by the National Center for Research Resources, National Institutes of Health.

ARIZONA STATE UNIVERSITY (http://www.asu.edu)

Department of Chemistry/Biochemistry (http://chemistry.asu.edu)
School of Earth and Space Exploration (http://sese.asu.edu)
Research Matters (http://researchmatters.asu.edu)
Tempe, Arizona USA

Carol Hughes | EurekAlert!
Further information:
http://www.asu.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>