Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Embryos exposed in 3-D

08.05.2006


New method can identify what genes do, test drugs’ safety



Utah and Texas researchers combined miniature medical CT scans with high-tech computer methods to produce detailed three-dimensional images of mouse embryos – an efficient new method to test the safety of medicines and learn how mutant genes cause birth defects or cancer.

"Our method provides a fast, high-quality and inexpensive way to visually explore the 3-D internal structure of mouse embryos so scientists can more easily and quickly see the effects of a genetic defect or chemical damage," says Chris Johnson, a distinguished professor of computer science at the University of Utah.


A study reporting development of the new method – known as "microCT-based virtual histology" – was published recently in PLoS Genetics, an online journal of the Public Library of Science.

The study was led by Charles Keller, a pediatric cancer specialist who formerly worked as a postdoctoral fellow in the laboratory of University of Utah geneticist Mario Capecchi. Keller now is an assistant professor at the Children’s Cancer Research Institute at the University of Texas Health Science Center in San Antonio.

University of Utah co-authors of the study are Johnson – who directs the university’s Scientific Computing and Imaging Institute – Capecchi, medical student Mark S. Hansen and several members of Johnson’s institute: computer science undergraduate Thomas Johnson III, research assistant Lindsey Healey and former associate director Greg M. Jones, who now is state science advisor to Utah Gov. Jon Huntsman Jr.

Scientists often use mouse embryos both to learn what genes do and to test the safety of new drugs and household chemicals. By disabling or "knocking out" a gene, researchers can see what goes wrong in the mouse embryo and thus learn the gene’s normal function, or learn how a mutant gene can cause cancer. Mouse embryos also are sensitive to toxicity from chemicals, so new medicines and chemicals are tested on them to see if any defects develop, indicating the safety for humans and their unborn embryos.

But the traditional method of histology – the anatomical study of the microscopic structure of living tissues – has been difficult and time-consuming. Mouse embryos with genetic mutations or damage from toxic chemicals are killed, embedded in wax, sliced into thin sections, then stained and placed on slides for examination under a microscope.

The new, faster and inexpensive method is called "virtual histology" because it uses computer visualization techniques to convert X-ray CT scans of mouse embryos into detailed 3-D images showing both the mouse’s exterior and interior.

Instead of being sliced up physically, mouse embryos are stained with special dyes. Traditional CT scans take a series of X-ray images representing "slices" through the body, and they primarily "see" bone and other hard tissues such as cartilage. In the new microCT virtual histology, the special dyes permeate the skin and other membranes, which are still permeable in an embryo.

"This technique allows us to get at a lot more tissues other than bone, such as internal organs, which [conventional] CT scans can’t pick up," Johnson says.

Johnson and his team wrote a computer algorithm – a problem-solving formula in computer software – to take the CT scan data and automatically distinguish various organs and structures in the mouse embryo. The "virtual rendering" of the CT scan data also includes a virtual light source so the 3-D embryo image includes shadows that make it easier for the human eye to understand and interpret the image.

The embryo images can be made transparent or have cutaways so that internal organs and body parts are visible. And the detail they show is exquisite – revealing features as small as one-tenth the thickness of a human hair.

The idea is to allow geneticists to quickly examine large numbers of embryos, each with a different gene disabled, so that the normal function of many genes can be determined faster than with existing methods.

Keller says the U.S. Food and Drug Administration and Environmental Protection Agency require drug and chemical manufacturers, respectively, to test their new products, but that such tests often are subjective. The new method "allows chemical and drug companies to conduct these studies in a much more quantitative way, improving upon the safety of the products we find in our homes," he adds.

Keller and a colleague have founded a company named Numira Biosciences, which plans to make the virtual histology method available through the sale of kits and imaging services.

The study was published online in the April 28 issue of PLoS Genetics.

Chris Johnson | EurekAlert!
Further information:
http://www.utah.edu

More articles from Information Technology:

nachricht Reversing cause and effect is no trouble for quantum computers
20.07.2018 | Centre for Quantum Technologies at the National University of Singapore

nachricht Study suggests buried Internet infrastructure at risk as sea levels rise
18.07.2018 | University of Wisconsin-Madison

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>