A.
New Insight into Green Tea Extract as an Anti-cancer Agent
Narrator: This is Science Today. A UCLA Jonsson Cancer Center study offers new insight into how green tea extract has potential as an anti-cancer agent. Jian Rao, an associate professor of epidemiology and pathology, says their study focused on bladder cancer cell lines.
Rao: We use a unique model system. These cell lines are both from the same individuals, so they genetically are similar. One can produce tumor the other one cannot. So, when you compare these two cell lines, we can learn quite a bit of biology to study the cancer mechanisms.
Narrator: Rao says the main finding of their study is that green tea extract selectively affects the cancer cells, but not the normal cells.
Rao: Furthermore, we demonstrate that the green tea affects the movement of the cell and also, we show the mechanisms of how that affects the movement of the cells. This is important clinically because more than likely green tea either is used as a drug to prevent cancer or can be used to treat the cancer patient.
Narrator: For Science Today, I'm Larissa Branin.
B.
Study Focuses on Complicated Sister Relationships
Narrator: This is Science Today. Sisters can be the best of friends, but they can sometimes be the worst of enemies. Just what shapes the complicated relationship between sisters was the focus of a study conducted by sociologist Marcia Millman of the University of California, Santa Cruz.
Millman: I started noticing that a lot of people that I knew, especially as they approached middle age, were having painful conflicts with their sisters and it really drove them crazy and I began to wonder why this would happen – why people who had always been close would suddenly have difficulties as they became middle-aged.
Narrator: Rather than the obvious reasons, such as dealing with divorce or becoming caregivers to aging or sick parents, Millman found that middle-aged sisters, who may now have more time to bond, get into trouble when they fall back into childhood roles.
Millman: I think the key to sisters who get along when they get older is that they really keep current, they don't just see each other in the context of the family where I think you do tend to fall into old patterns.
Narrator: Millman adds it's never too late to improve a sister relationship. For Science Today, I'm Larissa Branin.
C.
An Asthma Vaccine in the Works
Narrator: This is Science Today. About 20 million Americans suffer from asthma, a disease that causes airways of the lungs to tighten. Asthma medications control the symptoms, but scientists have developed an asthma vaccine, which in animal studies, has stopped the disease. Cell biologist Charles Plopper of the University of California, Davis says the vaccine works by modifying the immune system.
Plopper: There's a whole set of receptors that are on the surfaces of cells that respond to various types of agents. This is DNA that comes from a bacterium – it's a bacterial type of DNA form and there is one receptor that it responds to specifically. And that generates the type of response that would be to an infection – not an allergic response, but an infectious response.
Narrator: This causes the body to recognize the bacterial DNA as a foreign substance, so the immune system is activated to fight off what appears to be an infection. The vaccine also reversed asthma-induced lung damage. Tests in humans are now being conducted. For Science Today, I'm Larissa Branin.
D.
Cutting-Edge Technology Used to Detect Mad Cow Disease
Narrator: This is Science Today. Mad cow disease was first recognized in the mid-1980s in Europe. It's a neurological disease in which an abnormal protein gets into the brain and causes the brain to look like Swiss cheese. This protein passes through feed to the cow and there have been a few cases of a similar disease in humans. Jim Cullor, a veterinary professor at the University of California, Davis, led a team that developed a new livestock feed test that guards against mad cow disease.
Cullor: What this test does is apply forensic techniques, DNA techniques in enhancing the detection of contaminants in the feed. This is a new generation of assay, it's very modern, it's very cutting edge, but it's a technique that can be applied across the nation and around the world.
Narrator: Before this new feed test was developed, federal regulators had to rely on tests that were lengthier and less accurate.
Cullor: We're working on making it a rapid test that can be used both from a regulatory perspective and even down on the farm. Right now we're down to about a five-hour turnaround time.
Narrator: For Science Today, I'm Larissa Branin.
E. How Our Bodies Deal with Acute and Chronic Stress
Narrator: This is Science Today. Our bodies are well designed to deal with acute stress, such as the famed ‘fight or flight' response when we're in danger. In that case, the brain triggers the stress hormone cortisol to flood our body and then signals it to shut off. University of California, San Francisco psychologist Elissa Epel says the problem today is we don't deal with acute stress as much as our ancestors did.
Epel: We're really adapted to run across the savanna, fleeing from a predator, so you get this huge stress response and then it turns off and no problem, our bodies can do that. The problem is that we deal with these more chronic stressors day-to-day.
Narrator: Chronic stress can be the result of many instances of acute stress or a response to a difficult job, relationship or illness.
Epel: What happens in the brain with chronic stress is our bodies are flooded with more cortisol and the worst part of it is, over time, over years, this high cortisol – this negative feedback loop is all worn out and it doesn't shut off, so that we have more chronically high levels of cortisol.
Narrator: And this can lead to a variety of health problems. For Science Today, I'm Larissa Branin.
