“With this methodology, we have advanced methods for tracing metabolic pathways that are perturbed in disease,” says senior author Fariba Assadi-Porter, a UW-Madison biochemist and scientist at the Nuclear Magnetic Resonance Facility at Madison. “It’s a cheaper, faster, and more sensitive method of diagnosis.”
The researchers studied mice with metabolic symptoms similar to those seen in women with polycystic ovary syndrome (PCOS), an endocrine disorder that can cause a wide range of symptoms including infertility, ovarian cysts, and metabolic dysfunction. PCOS affects approximately 1 in 10 women but currently can only be diagnosed after puberty and by exclusion of all other likely diseases – a time-consuming and frustrating process for patients and doctors alike.
“The goal is to find a better way of diagnosing these women early on, before puberty, when the disease can be controlled by medication or exercise and diet, and to prevent these women from getting metabolic syndromes like diabetes, obesity, and associated problems like heart disease,” Assadi-Porter says.
The researchers were able to detect distinct metabolic changes in the mice by measuring the isotopic signatures of carbon-containing metabolic byproducts in the blood or breath. They injected glucose containing a single atom of the heavier isotope carbon-13 to trace which metabolic pathways were most active in the sick or healthy mice. Within minutes, they could measure changes in the ratio of carbon-12 to carbon-13 in the carbon dioxide exhaled by the mice, says co-author Warren Porter, a UW-Madison professor of zoology.
One advantage of the approach is that it surveys the workings of the entire body with a single measure. In addition to simplifying diagnosis, it could also provide rapid feedback about the effectiveness of treatments.
“The pattern of these ratios in blood or breath is different for different diseases – for example cancer, diabetes, or obesity – which makes this applicable to a wide range of diseases,” explains Assadi-Porter.
The technology relies on the fact that the body uses different sources to produce energy under different conditions. “Your body changes its fuel source. When we’re healthy we use the food that we eat,” Porter says. “When we get sick, the immune system takes over the body and starts tearing apart proteins to make antibodies and use them as an energy source.”
That shift from sugars to proteins engages different biochemical pathways in the body, resulting in distinct changes in the carbon isotopes that show up in exhaled carbon dioxide. If detected quickly, these changes may signal the earliest stages of disease.
The researchers found similar patterns using two independent assays – nuclear magnetic resonance spectroscopy on blood serum and cavity ring-down spectroscopy on exhaled breath. The breath-based method is particularly exciting, they say, because it is non-invasive and even more sensitive than the blood-based assays.
In the mice, the techniques were sensitive enough to detect statistically significant differences between even very small populations of healthy and sick mice.
The current cavity ring-down spectroscopy analysis uses a machine about the size of a shoebox, but the researchers envision a small, hand-held “breathalyzer” that could easily be taken into rural or remote areas. They co-founded a company, Isomark, LLC, to develop the technology and its applications. They hope to explore the underlying biology of disease and better understand whether the distinctive biochemical changes they can observe are causative or side effects.
Funding for the new study came from the National Institutes of Health, Wisconsin Institutes for Discovery, Rodale Foundation, and the Farmers Advocating for Organics fund. The other co-authors are Julia Haviland, Marco Tonelli, and Dermot Haughey, all at UW-Madison.
The full article, which may require a subscription, is online at http://dx.doi.org/10.1016/j.metabol.2011.12.010.
-- Jill Sakai, email@example.com, (608) 262-9772
Jill Sakai | Newswise Science News
Visualizing gene expression with MRI
23.12.2016 | California Institute of Technology
Illuminating cancer: Researchers invent a pH threshold sensor to improve cancer surgery
21.12.2016 | UT Southwestern Medical Center
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction