August 10, 2006, 7:07 AM CT

Predictors Of Breast Cancer

Breast cancer researchers at the University of North Carolina at Chapel Hill have identified a number of activity patterns in the genes of individual tumors that make them biologically different from others. These findings could provide valuable clinical information such as how likely the tumors are to be invasive, how well they might respond to different treatments and how likely they are to recur or spread.

Currently, doctors treating patients with breast cancer make treatment decisions and predictions based largely on the location and size of the tumor and if the cancer has spread, or metastasized, to lymph nodes and distant sites of the body.

But not all patients who are similar in terms of these clinical indicators get the same benefits from treatment.

These new findings could remedy that situation. Such differences in gene activity may be used as biomarkers to identify which treatments can be individually matched.

Over the past five years, gene expression profiles have been identified that appear to be predictive for cancer patients, especially for breast cancer patients. But these tests show very little overlap in their gene lists, and thus it is not known just how distinct these different assays might be.

According to Dr. Charles M. Perou, assistant professor of genetics and pathology at the UNC School of Medicine and a member of the UNC Lineberger Comprehensive Cancer Center, some of the predictive assays are available commercially and others are under study in clinical trials in which treatment decisions, including whether or not to use chemotherapy, are being made based on them.........

Posted by: Jessica      Permalink         Source

August 8, 2006, 9:56 PM CT

Teamwork: Where The Weak Help The Strong

Group work is the name of the game in a number of companies. The thinking is that workers will learn more and help each other when they are put into groups composed of people with a variety of expertise. But does this always happen? Some recent research suggests that it may not. at least not always.

"In order to understand how things happen in groups, you need to be aware of the group's hierarchy of status and influence," said Stuart Bunderson, associate professor of organizational behavior at the Olin School of Business at Washington University in St. Louis. "Those hierarchies can actually get in the way of some really important group goals like member-to-member helping and knowledge exchange".

In a co-authored study, Bunderson observed that group status hierarchies that form around perceptions of relative expertise can have some dysfunctional side effects. Specifically, he observed that group members felt more committed to and were more likely to help those members who were perceived to have a higher level of expertise - and were therefore higher status. In other words, the less expert members were helping the more expert members instead of the other way around! And this propensity to ingratiate oneself with the more expert members was particularly pronounced for members who were themselves perceived to be more expert.........

Posted by: Jessica      Permalink         Source

August 8, 2006, 0:31 AM CT

System To Put Wastewater To Work

In the midst of the worldwide energy crisis, researchers at Washington University in St. Louis have been continuing their work on a microbial fuel cell that generates electricity from wastewater. Advances in the design of this fuel cell in the last year have increased the power output by a factor of 10 and future designs, already in the minds of the researchers, hope to multiply that power output by 10 times again. If that goal can be achieved, the fuel cell could be scaled up for use in food and agricultural industries to generate electrical power - all with the wastewater that today goes right down the drain.

Lars Angenent, Ph.D., assistant professor of chemical engineering, and a member of the University's Environmental Engineering Science Program, has devised a continually fed upflow microbial fuel cell (UMFC). In a paper published online in the Environmental Science Technology, Angenent describes how wastewater enters from the bottom of a system and is continuously pumped up through a cylinder filled with granules of activated carbon. Many previous microbial experiments used closed systems with a single batch of nutrient solution, but because this system is continuously fed from a fresh supply of wastewater, Angenent's UMFC has more applications for industry since wastewater is continually outputted during industrial production.........

Posted by: Jessica      Permalink         Source

August 5, 2006, 11:59 PM CT

Broad Talk Illuminates Genetics

For decades, researchers have been teasing out the secrets of the human genome, hoping to learn more about what makes the body function and why things sometimes go wrong.

Now, researchers are on the brink of identifying genes that play a major role in a variety of diseases, thanks to recent rapid advances in DNA sequencing technology, as per Dr. David Altshuler, director of the program in medical and population genetics at the Broad Institute of MIT and Harvard.

Altshuler talked about "expectations for improved therapies in the era of genomic medicine" at the final installment of the "Midsummer Nights' Science" lecture series held at the Broad Institute on Aug. 1.

Scientists at the Broad and around the world are using new sequencing technology to look for genes that are associated with the development of diseases such as diabetes, multiple sclerosis, lupus, bipolar disorder and autism, among a number of others.

The new research builds on the 2003 completion of the human genome sequence, which showed that while most humans share the vast majority of their genetic sequence (about 99.9 percent), variations known as single nucleotide polymorphisms, or SNPs, occur within the other.1 percent of the genome. Those variations are what make each individual unique.........

Posted by: Jessica      Permalink         Source

August 1, 2006, 6:54 AM CT

Curry And Onions May Prevent Colon Cancer

A small but informative clinical trial by Johns Hopkins scientists shows that a pill combining chemicals found in turmeric, a spice used in curries, and onions reduces both the size and number of precancerous lesions in the human intestinal tract.

In the study, published in the recent issue of Clinical Gastroenterology and Hepatology, five patients with an inherited form of precancerous polyps in the lower bowel known as familial adenomatous polyposis (FAP) were treated with regular doses of curcumin (the chemical found in turmeric) and quercetin, an antioxidant in onions, over an average of six months. The average number of polyps dropped 60.4 percent, and the average size dropped by 50.9 percent, according to a team led by Francis M. Giardiello, M.D., at the Division of Gastroenterology, The Johns Hopkins University School of Medicine, and Marcia Cruz-Correa, M.D., Ph.D., at Johns Hopkins and the University of Puerto Rico School of Medicine.

"We believe this is the first proof of principle that these substances have significant effects in patients with FAP," says Giardiello.

Typically typically familial adenomatous polyposis is a disorder that runs in families and is characterized by the development of hundreds of colorectal adenomas (polyps) and eventual colon cancer. Recently, nonsteroidal anti-inflammatory drugs (NSAIDs) have been used to treat some patients with this condition, but these compounds often produce significant side effects, including gastrointestinal ulcerations and bleeding, according to Giardiello.........

Posted by: Jessica      Permalink         Source

July 31, 2006, 6:52 AM CT

Malignant Melanoma Secretes Embryo Protein

A Northwestern University research group has discovered that aggressive melanoma cells secrete Nodal, a protein that is critical to proper embryo formation.

An article describing this research was published recently in the advanced online issue of the journal Nature Medicine.

The researchers identified the potent and highly unstable embryonic growth factor by injecting aggressive melanoma cells into developing zebrafish embryos, which were used as "biosensors" for tumor cell-derived signals, and were consequently able to induce ectopic (abnormal) embryonic skull and backbone (axes) formation.

"This finding highlights the convergence of tumorigenic and embryonic signaling pathways. From a translational perspective, Nodal signaling provides a novel target for treatment of aggressive cancers such as melanomas," said Mary J. C. Hendrix, the corresponding author, of Children's Memorial Research Center where the discovery was made.

Hendrix is president and scientific director of the Children's Memorial Research Center, professor of pediatrics at Northwestern University Feinberg School of Medicine and a member of the executive committee of The Robert H. Lurie Comprehensive Cancer Center of Northwestern University. Jolanta M. Topczewska and Lynne-Marie Postovit, from Children's Memorial Research Center, co-led the study.........

Posted by: Jessica      Permalink         Source

July 28, 2006, 10:42 PM CT

Radiation Cocktail For Breast Cancer

A carefully determined mixture of electron and x-ray beams precisely treated breast tumors while significantly reducing collateral skin damage in 78 patients, researchers will report on August 1 at the annual meeting of the American Association of Physicists in Medicine in Orlando. The key to choosing the right mixture of beams, as well as their individual properties, was a sophisticated computer approach developed by medical physicists Jinsheng Li, Ph.D. (Jinsheng.Li@fccc.edu) and Chang-Ming Ma, Ph.D. of Fox Chase Cancer Center in Philadelphia.

In treating shallow tumors such as those that occur in the breast, physicians have been turning to mixed-beam radiation therapy (MBRT), which employs separate beams of electrons and photons (x-rays). The two types of radiation complement one another, as electrons generally travel to shallow depths while the x-rays can penetrate to deeper parts of the tumor as needed.

However, each beam interacts in complex ways with its environment, making their exact path to the tumor region hard to predict. Nonetheless, physicists can calculate the probability for a given beam to follow a desired trajectory.

Therefore, Li and Ma use computers to simulate billions of trips of each beam to the unique landscape of each tumor. Gathering the statistics from these billions of trials, they determine the best beam properties and mixtures.........

Posted by: Jessica      Permalink         Source

July 26, 2006, 5:20 PM CT

Identifying Medical Proxy

One-third of married individuals choose someone other than their spouse as a surrogate for medical decision-making. And more often than not, when adult patients chose a parent, sibling or child, they prefer their mothers, sisters and daughters to serve as medical proxies over their fathers, brothers and sons.

These are among the results of a study on advance care planning conducted by Northwestern University researcher K. Michael Lipkin, M.D., available in the online early edition of the Journal of General Internal Medicine (http://www.blackwell-synergy.com/toc/jgi/0/0). Lipkin is assistant professor of clinical preventive medicine at Northwestern University Feinberg School of Medicine.

The finding that 33 percent of the married patients in the study did not choose their spouse as surrogate is noteworthy, because physicians regularly look to spouses as informal surrogates.

Additionally, over a quarter of survey participants chose someone other than the person identified as an emergency contact to act as proxy in medical decision-making.

"When patients choose a surrogate who is not the person doctors would usually consult or who would not become empowered as a substitute decision-maker under state laws, physicians are alerted to engage these patients in an advance care planning process that ensures the formal appointment of their desired health care agent," Lipkin said.........

Posted by: Jessica      Permalink         Source

July 22, 2006, 10:46 PM CT

Watching Real-time Chemical Activity In Cells

Attempts to identify potential drugs that interfere with the action of one particular enzyme associated with heart disease and similar health problems led researchers at Johns Hopkins to create a new tool and new experimental approach that allow them to see multiple, real-time chemical reactions in living cells. Their report on the work is published July 21 in the journal ACS Chemical Biology.

Most current drug development operations test chemicals on enzymes isolated from their normal environs and then take further steps to see if the chemical can get into the cell to do its work, and figure out how poisonous the chemical is to a cell.

"Living cells are critical to our work because they show us how and what is actually happening in a normal context and time span when a chemical is added," says Jin Zhang, Ph.D., an assistant professor of pharmacology and molecular sciences in Hopkins' Institute for Basic Biomedical Sciences.

Testing chemicals on enzymes in living cells provides the opportunity to find potential drugs that work in new ways. For example, using living cells allows scientists to "see" where in the cell chemicals do their work. Researchers could then design new drugs to go to specific places within cells to work more efficiently. Also, streamlining the one-at-a-time approach offers the chance to study - and rule out or in - a number of potentially useful chemicals at once.........

Posted by: Rose      Permalink         Source

July 18, 2006, 6:05 AM CT

Communication Signal For Tissue Development

Researchers at Rensselaer Polytechnic Institute have discovered a communication signal between cells that plays an important role in cell adhesion and detachment. The finding provides new information about how cells and tissues determine when to let go from surfaces during new growth, according to the researchers.

Our discovery of this new signaling pathway adds to fundamental information about how cells work together during the remodeling of tissues and organs," said Andrea Page-McCaw, assistant professor of biology at Rensselaer. "This finding also may provide clues about the basic mechanisms of inflammation and wound healing in vertebrates".

Page-McCaw's laboratory studies the fruit fly as a model system to better understand a group of genetic enzymes called matrix metalloproteinases (MMPs). Fruit flies have two distinct MMPs, compared to 22 such enzymes found in humans and mice. In previous work, Page-McCaw found that both MMPs present in fruit flies are critical to their survival.

"Although MMP enzymes have been linked to disease progression, their normal function is to help in tissue growth and wound healing," Page-McCaw said. "MMP research eventually could lead to therapeutics for a range of illnesses, including cancer and arthritis".

Page-McCaw studies development and remodeling of the airway system, or tracheae, in fruit fly larvae with normal and mutant MMPs to determine how those genes contribute to normal function. In this work, she and her colleagues found that one of the MMPs chops off a piece of a protein called Ninjurin A, which is located at the surfaces of cells. The liberated piece of Ninjurin A protein then signals to other cells that it is time to detach from their surface, both in isolated cells grown in culture and in whole flies. When tracheal cells fail to detach from the insect exoskeleton, the tracheae do not grow properly and break.........

Posted by: Jessica      Permalink         Source

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