Featured Research

from universities, journals, and other organizations

Unsticking The "Glue" In Blood Cells Could Save Lives

August 26, 1998
Johns Hopkins University
It's wildfire season, and researchers hope to be in the midst of such blazes, during the month of September. Scientists funded by the National Science Foundation (NSF) and affiliated with the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, will fly a highly instrumented C-130 research aircraft around and over dangerous wildfires that may ignite this season in the United States.

Scientist Tries to Restrain Platelets That Form Killer Clots and Help Spread Cancer

Related Articles

Platelets, the blood cells that help a cut finger stop bleeding, can also take a deadly turn as they course through veins and arteries. When platelets in the bloodstream clump together as a clot, they can trigger a heart attack or a stroke. When platelets stick to a moving cancer cell, they may hide it from the body's natural defenses.

A Johns Hopkins University scientist is working on ways to disable platelets' unhealthy habits while preserving their ability to halt blood loss. The goal, says Konstantinos Konstantopoulos, is to unlock the secrets of the tacky molecules that platelets use to cling to each other and to the walls of blood vessels.

To do this, Konstantopoulos, an assistant professor of chemical engineering, has set up equipment that simulates the flow of human blood beneath a microscope. A video camera attached to the microscope lets him record and study cells that are moving as they would through blood vessels. With this equipment, he has begun testing medications that could keep platelets from using their stickiness in ways that jeopardize human health.

Under normal conditions, platelets simply circulate through the body along with red and white blood cells, posing no threat. "If you look inside the blood vessels of a healthy person, you'll see the platelets moving passively without interacting with each other or with the walls of the blood vessel," Konstantopoulos explains.

If the skin is cut, sticky molecules appear on the surface of the platelets, which rush to the site and adhere to the broken vessel wall to prevent blood loss. But sometimes, a medical disorder can set off the sticky response. If these platelets stick to each other and form a clot that stops critical blood flow to the heart or the brain, cardiac arrest or a stroke may occur. This leaves researchers with a challenge: Can platelets continue to control bleeding without forming lethal blood clots?

Fortunately, two different molecules appear to be involved in these processes. Generally, a molecule called glycoprotein Ib assists the platelets in adhering to a blood vessel wall, which is critical to controlling blood loss. But a molecule called glycoprotein IIb IIIa usually allows platelets to stick to one another. "So what the drug companies want to do," Konstantopoulos explains, "is to block the receptor for IIb IIIa, without affecting Ib. That way, you can reduce the risk of clots while continuing to limit blood loss."

In related research, the Hopkins scientist is trying to understand how platelets manage to stick to cancer cells that have broken off from a primary tumor and entered the bloodstream. "There is some evidence that these loose tumor cells can interact with platelets," Konstantopoulos says. "We think the platelets mask the cancer cells so that the body's defense mechanisms don't recognize that something foreign has invaded the bloodstream. As a result, the cancer cells are free to move anywhere, stick someplace and form another colony."

This life-threatening process is called cancer metastasis. The Hopkins researcher wants to block metastasis so that a surgeon can cut away the primary tumor without worrying that the disease will spread elsewhere. "I want to identify the molecules on the platelets and the tumor cells that allow them to stick together," he says. "Then, presumably, if you inject agents that prevent this adhesion, the body's natural defenses will recognize the cancer cell and fight it."

With these aims in mind, Konstantopoulos has obtained funding from the Whitaker Foundation to begin testing pharmacological agents that may keep platelets from sticking to each other or to cancer cells. He brings to this line of research the tools and techniques of both a chemical engineer and a biologist. Instead of simply looking at cells that remain still beneath a microscope, he studies them as they flow through tubes.

"The focus of all of this research is to learn how cells stick to other cells or to vessel walls under flow conditions," Konstantopoulos explains. "In the lab, I can simulate the conditions that occur inside the blood vessels, inside the body. In the past, biologists mainly looked at how cells interact under static conditions. We are interested in these biological processes, but we are also interested in how the flow of blood can affect these processes. We have found differences."

Related Web Pages:

Johns Hopkins Department of Chemical Engineering:http://www.jhu.edu/~cheme/ChemE.html

Konstantinos Konstantopoulos' Home Page:http://www.jhu.edu/~cheme/Konst.html

Story Source:

The above story is based on materials provided by Johns Hopkins University. Note: Materials may be edited for content and length.

Cite This Page:

Johns Hopkins University. "Unsticking The "Glue" In Blood Cells Could Save Lives." ScienceDaily. ScienceDaily, 26 August 1998. <www.sciencedaily.com/releases/1998/08/980826083220.htm>.
Johns Hopkins University. (1998, August 26). Unsticking The "Glue" In Blood Cells Could Save Lives. ScienceDaily. Retrieved November 29, 2014 from www.sciencedaily.com/releases/1998/08/980826083220.htm
Johns Hopkins University. "Unsticking The "Glue" In Blood Cells Could Save Lives." ScienceDaily. www.sciencedaily.com/releases/1998/08/980826083220.htm (accessed November 29, 2014).

Share This

More From ScienceDaily

More Health & Medicine News

Saturday, November 29, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
WHO Says Male Ebola Survivors Should Abstain From Sex

WHO Says Male Ebola Survivors Should Abstain From Sex

Newsy (Nov. 28, 2014) — WHO cites four studies that say Ebola can still be detected in semen up to 82 days after the onset of symptoms. Video provided by Newsy
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 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.


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


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