Program 919,
  December 6 , 2005


A. A Radiology Technique Offers an Alternative to Colonoscopy

Narrator: This is Science Today. Virtual colonoscopy uses CAT scan technology to study the colon. One of the advantages of this radiology technique over the traditional methods is that it's less invasive. Judy Yee, a vice-chair of radiology at the University of California , San Francisco , explains that there's no need to insert a scope throughout the colon.

Yee: So it's a safer exam in that you don't have the risk of puncturing a hole in the colon or of infection or of bleeding.

Narrator: The colonoscopy is still considered the gold standard test due to its high sensitivity for finding cancer and precursor lesions, or polyps.

Yee: However, in spite of colonoscopy having been around for many, many years, if you look at the percentage of patients over the age of fifty who come in for colon cancer screening, it's less than thirty percent. So, the majority of patients who should come in for colon cancer screening are not coming in and I think that virtual colonoscopy definitely offers an alternative.

Narrator: For Science Today, I'm Larissa Branin.

B. Studying Macular Degeneration on a Biological Level

Narrator: This is Science Today. Cell and molecular biologists at the Neuroscience Research Institute at the University of California , Santa Barbara are studying age-related macular degeneration on a biological level. Don Anderson, director of the institute's Center for the Study of Macular Degeneration, says ten years ago, there was very little research devoted to this blinding disease.

Anderson : What we decided to do was try to approach the problem from a cell biological level and the easiest way that we came up with approaching that was to focus on deposits that are characteristic of the disease called drusen. Our initial hypothesis was that if we were able to discern what the molecular composition of these drusen were, that that would give us insights into the disease process.

Narrator: Age-related macular degeneration is the leading cause of irreversible blindness in individuals over the age of sixty.

Anderson : By way of definition, a macula is Latin for spot and the spot in this case is a portion of the central retina and it lies just adjacent to the optic nerve.

Narrator: For Science Today, I'm Larissa Branin.

C. The Rapid Detection of Biological Agents

Narrator: This is Science Today. A technology that can rapidly detect biological agents in office buildings or in ports of entry such as airports and train stations has been developed by researchers at the Lawrence Livermore National Laboratory. Eric Gard, who leads the Lab's Defense Biology and Biosciences division, says it's called a bioaerosol mass spectrometry system, or BAMS.

Gard: BAMS is autonomous, does the sampling and detection itself, but it does it in a time scale of seconds rather than hours.

Narrator: Previous technologies took hours and Gard says when it comes to detecting biological agents, time is of essence.

Gard: We're looking at all classes of biological threat we're looking at spores, vegetative cells, viruses and toxins. So, examples of the bacteria would be anthrax, plague and CDC has a list of other things that are of interest to them in the viral and toxin category that we're also looking for.

Narrator: For Science Today, I'm Larissa Branin.

D. Measuring Blood Flow in the Brain to Detect Alzheimer's Disease

Narrator: This is Science Today. A team of research scientists at the San Francisco Veterans Affairs Medical Center are working to identify imaging markers for detection of Alzheimer's disease, as well as other types of dementia. According to study leader Norbert Schuff, one approach in the past that has been very successful is to measure brain tissue loss.

Schuff: But, you can imagine that before you lose neurons or tissue, there's probably another process, which makes the tissues pathological or sick or ill before it is really lost and shrinks. And people believe that some of the processes involve some kind of a degeneration which is then related to reduced blood flow.

Narrator: Schuff has been studying a non-invasive technique that measures blood flow called arterial spin labeling and has found it can differentiate between patients with Alzheimer's disease and another dementia.

Schuff: This is still at the level of research and the level of research means that we can not use this technique for individual diagnosis.

Narrator: For Science Today, I'm Larissa Branin.

E. Understanding the Mechanisms of Human Bone

Narrator: This is Science Today. Material scientists at the Lawrence Berkeley National Laboratory made use of sophisticated technology used to conduct research on advanced materials, composites and ceramics, to study the mechanisms of human bone. Robert Ritchie, a senior scientist at the Lab and chairman of Material Sciences at the University of California , Berkeley led the study.

Ritchie: Even though bone is pretty tough material, mechanistically, it behaves much more like a ceramic than it does a metal. We basically used all the techniques that we've learned and developed and analyzed in fractures and ceramics and applied them to these biological materials.

Narrator: The researchers were able to look at three-dimensional x-ray computed tomography images to get extremely high resolution views of the human bone. Ritchie says he's interested in the mechanism by which the bone breaks.

Ritchie: If you know what the mechanism is and you know how it relates to the structure, you can then relate that back to what caused such a structure to change.

Narrator: For Science Today, I'm Larissa Branin.



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