Featured Research

from universities, journals, and other organizations

Contrast Agent Trials In Swine

Date:
October 18, 2007
Source:
John Wiley & Sons, Inc.
Summary:
Mammography continues to be the method of choice for the early detection of breast cancer. However, because this technique is not as selective or specific as one would wish, and does not deliver reliable results for every level of tissue density, alternatives are being sought. Near-infrared fluorescence mammography, which works with rays of near-infrared light instead of X-rays, is a highly promising technique—although effective contrast agents have thus far been lacking.

Mammography continues to be the method of choice for the early detection of breast cancer. However, because this technique is not as selective or specific as one would wish, and does not deliver reliable results for every level of tissue density, alternatives are being sought. Near-infrared fluorescence mammography, which works with rays of near-infrared (NIR) light instead of X-rays, is a highly promising technique—although effective contrast agents have thus far been lacking.

A team led by John V. Frangioni at the Beth Israel Deaconess Medical Center of the Harvard Medical School in Boston, Massachusetts, has developed a contrast agent that makes visible the microcalcifications related to malignant breast tumors. The researchers report in the journal Angewandte Chemie that in validation trials in swine their new contrast agent distinguishes specific calcium salts in soft tissues, as well as depicting bones.

As breast cancer develops, calcium salts are deposited in breast tissue. These microscopic calcium deposits consist mostly of hydroxyapatite, a salt containing calcium and phosphate that is also present in bones.

As the basis of their NIR contrast agent, the researchers chose to use the osteoporosis drug pamidronate, a biphosphonate. Biphosphonates, which are also used for the treatment of bone metastases in breast cancer patients, preferentially bind to bone. Frangioni and his team attached a dye that both absorbs light and fluoresces in the NIR region of the spectrum to a pamidronate derivative. Light in this region of the spectrum penetrates especially well into living tissue without damaging it, and is also easy to detect.

Thanks to a simplified, reliable synthetic route to a new pamidronate derivative developed by Kumar R. Bhushan, the American team has now been able to synthesize large quantities of a contrast agent called Pam800—enough to run a trial with large animals. Pigs are particularly well suited to such trials because their organs are of approximately the same size as human organs.

As confirmed by surgical incisions, intravenously administered Pam800 reveals the bones of pigs with very high sensitivity. When hydroxyapatite is injected into the soft tissues, the contrast agent marks only the tiny hydroxyapatite crystals with high selectivity and sensitivity. This could allow it to selectively reveal malignant abnormal tissue. The swine trials demonstrated that the use of real-time NIR fluorescence images even make possible image-guided surgery of the soft tissues and bones.

Reference: Synthesis of Conjugatable Bisphosphonates for Molecular Imaging of Large Animals, Angewandte Chemie International Edition 2007, 46, 7969–7971 doi: 10.1002/anie.200701216


Story Source:

The above story is based on materials provided by John Wiley & Sons, Inc.. Note: Materials may be edited for content and length.


Cite This Page:

John Wiley & Sons, Inc.. "Contrast Agent Trials In Swine." ScienceDaily. ScienceDaily, 18 October 2007. <www.sciencedaily.com/releases/2007/10/071016131449.htm>.
John Wiley & Sons, Inc.. (2007, October 18). Contrast Agent Trials In Swine. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2007/10/071016131449.htm
John Wiley & Sons, Inc.. "Contrast Agent Trials In Swine." ScienceDaily. www.sciencedaily.com/releases/2007/10/071016131449.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microneedle Patch Promises Painless Pricks

Microneedle Patch Promises Painless Pricks

Reuters - Innovations Video Online (Oct. 18, 2014) Researchers at The National University of Singapore have invented a new microneedle patch that could offer a faster and less painful delivery of drugs such as insulin and painkillers. Video provided by Reuters
Powered by NewsLook.com
Raw: Nurse Nina Pham Arrives in Maryland

Raw: Nurse Nina Pham Arrives in Maryland

AP (Oct. 17, 2014) The first nurse to be diagnosed with Ebola at a Dallas hospital walked down the stairs of an executive jet into an ambulance at an airport in Frederick, Maryland, on Thursday. Pham will be treated at the National Institutes of Health. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Raw: Cruise Ship Returns to US Over Ebola Fears

Raw: Cruise Ship Returns to US Over Ebola Fears

AP (Oct. 17, 2014) A Caribbean cruise ship carrying a Dallas health care worker who is being monitored for signs of the Ebola virus is heading back to Texas, US, after being refused permission to dock in Cozumel, Mexico. (Oct. 17) Video provided by AP
Powered by NewsLook.com
Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

AFP (Oct. 17, 2014) All four suspected Ebola cases admitted to hospitals in Spain on Thursday have tested negative for the deadly virus in a first round of tests, the government said Friday. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins