Johns Hopkins Gazette: August 19, 1996

In Brief

Pain in the neck? Just think 'no'

The next time someone tells you that pain is all in your head, they could be at least partially right, according to a study led by School of Medicine researchers. Results suggest that "positive thinking" may help some people cope with pain better, while negative thoughts may worsen the pain by intensifying the anxiety everyone has about hurting.

In the study, presented Aug. 18 at the eighth annual World Congress on Pain in Vancouver, 72 people held their hands in ice water and concentrated either on positive, negative or neutral messages rehearsed before the tests. All were evaluated for pain anxiety in a written test as well.

The results found that people with high anxiety withdrew their hands from the ice water much sooner than people with a normal concern about pain, but that the positive messages nearly doubled the pain threshold and tolerance of both groups. Negative messages significantly lowered the pain threshold and tolerance in both groups. Threshold is the first feeling of pain; tolerance measures how long the pain can be withstood.

"These findings support our belief that most pain involves both a biological cause and the emotional response to it, and that treatment should address both these factors," said assistant professor Peter Staats, the study's lead author and director of pain medicine at Hopkins.

The study's positive messages were that ice water made wounds heal faster, improved blood flow, strengthened fingernail beds and had other medical benefits, while the negative messages were that ice water was harmful. The positive and negative groups also repeated terms--such as honesty or dishonesty, health or sickness, cleanliness or filth, sex or sexual abstinence--that cause positive and negative mental images and make the participants feel more relaxed or more stressed.

Johns Hopkins Imaging has two sites in operation

In a move to extend high-quality, convenient diagnostic radiology services to more of the metropolitan Baltimore community, Johns Hopkins HealthCare has formed Johns Hopkins Imaging with two sites already operating.

JHI at Green Spring Station in Lutherville and JHI at Towson are the first in what Hopkins officials envision as a network of high-quality imaging centers throughout Central Maryland. JHI is designed to meet the current and future needs of the community as dictated by the rapidly changing health care market.

Imaging services including X-rays, CT and high-field magnetic resonance imaging are performed at JHI at Towson, west of the Beltway at the Charles Street exit. JHI at Green Spring Station, an American College of Radiology-accredited mammography facility widely recognized as a regional center of excellence in breast care, offers mammography, breast biopsies, ultrasound, X-rays and bone densitometry studies.

Johns Hopkins HealthCare is a limited liability company that uses Hopkins and affiliated providers to dispense high-quality, affordable services to a large segment of Maryland's population. JHHC offers everything from preventive and primary medical care to specialist services and hospital care. JHI is the latest addition to the specialty services designed to benefit residents of Baltimore and surrounding counties.

New method developed to study deep space

University astronomers have devised a new technique that enables them to quickly measure the distances to the farthest galaxies, at last providing a large number of examples with which to test cosmological theories, and to study galaxy evolution and the nature of dark matter.

The new technique, called photometric-redshift astronomy, promises to provide a wealth of data, resolving a serious dilemma in cosmology research: if you know the distances to only a few galaxies in a given region of deep space, how can you be certain that those galaxies represent the universe at large?

With photometry, astronomers soon will know the distances to about 20,000 galaxies that are so far away the light now reaching Earth is from a time when the universe was only one-third its current age, perhaps more than 10 billion years ago, said Alexander Szalay, professor of physics and astronomy.

The method was used to confirm that elliptical galaxies had all but stopped evolving, whereas spiral galaxies, such as the Milky Way, still were undergoing dramatic evolution when the universe was a mere one-third its current age.

Astronomers usually use spectrographs to gauge the distances of objects in space by measuring their redshifts, or the degree to which their light has been stretched into longer wavelengths as they speed away from our place in the cosmos. But spectrographs require as much as 1,000 times more exposure time per object than photometry, making it impractical to measure the distances to the farthest galaxies.

It would take a full night of observing time to take a spectrograph of a single distant galaxy. But, in the same amount of time, astronomers can measure the distances to 1,000 galaxies of comparable range with the photometric-redshift technique.

The method works like this: Astronomers take photographs of regions of space using four separate filters, so that they have pictures in ultraviolet, blue, red and near-infrared light. The images are taken with telescopes equipped with charge-coupled devices, light-sensor chips used in video cameras that enable scientists to capture an image accurately.

By mathematically computing how much of each color an object emits, astronomers can tell how far away it is.

"We have discovered a very strong relation between the distance of the object and these colors," Szalay said, "I think now this has really taken off."

The method cannot replace spectroscopy, which reveals fine details about the composition and velocity of objects in space. Photometry provides only a crude spectrum, but it's accurate enough to measure the general distances of objects and it's the only practical way to measure the distances of large numbers of objects in deep space, said the astronomers, who have been developing the technique for about two years.

Clues to Alzheimer's protein behavior found

School of Medicine researchers have assembled the first clues to the behavior of presenilin, a protein linked to an inherited form of Alzheimer's disease.

In a report published in the July issue of Neuron, they show that presenilin normally cleaves in two and that a disease-causing mutation in presenilin can prevent the cleavage.

Cleavage is an important change for a protein and probably has a significant effect on what the protein does. If researchers can find where presenilin cleaves and the enzyme that cleaves it, intervening at this point with drugs or other treatments might be ideal, said Sangram Sisodia, associate professor of pathology and neuroscience.

Presenilin is a long protein that snakes in and out of the membranes of nerve cells. It is found in an altered form in nearly 60 percent of all "early onset" familial Alzheimer's disease cases, cases where symptoms first appear in patients in their late 20s to their late 50s.

Because presenilin is present only at very low levels, it is unlikely to be directly causing the widespread damage to nerve cells seen in Alzheimer's, but it may interfere with other proteins that could, Sisodia said. Like dominoes falling, a change in presenilin sets off a chain reaction.

According to Sisodia, mutated forms of presenilin may influence the formation of plaques in the brain that are among the earliest signs of Alzheimer's disease.

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