Progress reported on AIDS vaccineAlpha 1 Biomedicals Inc...

LIFE SCIENCES

December 01, 1992|By Liz Bowie

Progress reported on AIDS vaccine

Alpha 1 Biomedicals Inc. of Bethesda and CEL-SCI Corp. of Alexandria, Va., have passed another milestone in their quest to develop an AIDS vaccine.

The companies say researchers at San Francisco General Hospital found there was no evidence of safety problems in the first 16 healthy volunteers who received the vaccine. In addition, the data, recently reported in the medical journal AIDS Research and Human Retroviruses, showed that the volunteers had developed some immune system response.

However, the companies still have many hurdles to overcome, including getting the vaccine -- known as HGP-30 -- through a series of other tests to show it is effective. So far, "we have no evidence of a neutralizing antibodies," said Judith A. Hautala at Alpha 1.

The vaccine was first identified by Allan L. Goldstein, Alpha 1 board chairman. He formed a joint venture with CEL-SCI in 1986 to develop it.

The companies are trying to get the vaccine approved first as a treatment that could slow down the disease in people already infected with the virus that causes AIDS. Alpha manufactures the vaccine for trials.

To be licensed as a vaccine for healthy individuals, the vaccine must be tested on a much larger number of people before the Food and Drug Administration would consider approval.

The FDA requires several levels of testing. Results of the recent tests will be submitted to the FDA, which could rule that they meet requirements for the first phase of testing.

Still, final approval by the FDA would take years.

Oysters raised in float in Chester River

No more muddy oysters on the half shell? If some researchers have their way, oysters grown for slurping and stews won't ever touch the muddy bottom of the bay.

Suspended in a large float in the Chester River near Centreville is an experiment in aquaculture that researchers hope will allow them to grow oysters to market size more quickly. That would allow the oysters to elude the diseases MSX and Dermo, which do not cause any harm to humans but which are deadly to the shellfish.

The float has a series of drawers that hold the oysters closer to the surface of the water so that they get more oxygen and food as the nutrients float by.

The oysters could grow faster and be harvested within about a year, says Dr. Fred Wheaton, an agricultural engineer at the Maryland Institute for Agriculture and Natural Resources.

The technique, widely used in Japan and other Far Eastern countries, mimics the growing conditions that oysters experienced a century ago, before they were ravaged by overfishing and disease. The oysters grew in masses, like underwater islands, which were described as miles long and sometimes breaking the surface of the water.

But today the beds are merely small hills on the bay's muddy bottom.

In the past few years, oyster harvests have been a fraction of what they were even two decades ago. In the early 1970s Maryland's harvest was near 3 million bushels a year. Last year it was less than 300,000 bushels.

Dr. Wheaton said he and his colleagues, Eric Powell, a graduate student, and Doug Lipton, a marine economist, won't know for another growing season whether the technique is likely to work and be economical.

His biggest worry this winter is what the ice might do to his 20-by-40-foot float. Worlds End Aquaculture of Lutherville donated 2,000 oysters for the experiment.

HIV enzyme identified as cause of mutations

Pennsylvania State University chemists believe they have discovered how the human immunodeficiency virus, which causes AIDS, may develop mutations that make it resistant to drugs.

Chemistry Professor Stephen J. Benkovic and postdoctoral fellow James A. Peliska, who recently published their findings in XTC the journal Science, discovered that an enzyme in the virus may be responsible for adding extra material to the genetic code.

The virus invades the body by transforming the genetic material in its molecules -- RNA -- into the form of human genetic material -- DNA -- to survive.

The HIV-derived DNA then slips into the human cell's own DNA, where it is able to reproduce and then infect other cells.

While the concept is not new, the researchers described for the first time the details of how the process works.

Think of DNA as a closed zipper twisted into a spiral shape.

The HIV molecule constructs the first side of the DNA, one tooth at a time, by using the RNA as a template and chemicals from the human cell as building blocks. Then it uses the new DNA strand as a template to manufacture the other half of the two-sided DNA.

But the molecule is very sloppy at reproducing the DNA perfectly, often inserting a mistake into the code, thus causing a mutation of the virus.

Space station exhibit at Md. Science Center

The Maryland Science Center will give the public a chance to see the living and working conditions of astronauts in a traveling exhibit that will be open from today through Sunday.

NASA is lending the exhibit of the Space Station Freedom -- an international effort to put an advanced research laboratory in space in the mid-1990s -- to the science center to coincide with Technology Week events in Baltimore.

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