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Watching cholesterol - in the lab.

There is life after high school, but will it include a career in science? To help yourself decide, consider becoming an apprentice at the Agricultural Research Service. The 8-week program won't tie you down all summer - and probably will pay at least what you'd make at the local fast-food eatery.

What do three former research apprentices say about the program?

"The scientists showed me how to do the job, made sure I knew how, and then let me go at it," says college freshman Steven Crone.

"Some programs like this you have to pay for," adds freshman Glenn Flaim.

"I felt important, like I was contributing something," says Danielle Spearman, a high school senior.

All three worked last summer at ARS' Human Nutrition Research Center in Beltsville, Maryland. They helped scientists at the center's Lipid Nutrition Laboratory.

Lipids are fats. Without them. your body couldn't store energy, produce hormones, keep cell and tissue membranes intact and supple, or perform many other functions.

But your health can suffer from a high-fat diet, especially one with too much cholesterol and saturated fat - the kind that turns solid at room temperature.

What really matters, as Crone, Flaim, and Spearman learned, is what happens after fats arrive in the bloodstream in the form of fatty acids. In some people, fats tend to accumulate along artery walls. This hinders blood flow, raises blood pressure, and increases the risk that a blood clot can block an artery and cause a heart attack.

Contrary to popular belief, cholesterol isn't fat - it's a steroid alcohol molecule. It occurs naturally in animal tissues, and your body also makes it.

High blood cholesterol is often associated with high consumption of saturated fat. So eating "cholesterol-free" ol-free" potato chips fried in palm oil - which is high in saturated fat - isn't going to help you watch your cholesterol.

Cholesterol circulates in the blood in two principal types of special proteins called lipoproteins. One type is the artery-clogging "bad cholesterol" or LDL, which stands for low-density lipoprotein. The other type, HDL or high-density lipoprotein, helps counteract LDL.

"You will think of LDL'S as delivery trucks, depositing fatty acid esters of cholesterol in blood vessels, and HDL'S as garbage trucks, taking them back to the liver where they're broken down," says ARS chemist Elliott Berlin.

He notes that earlier studies by ARS and many other researchers have established the overall value of HDL and unsaturates. But there is considerable debate on whether the risk of cardiovascular disease - as well as cancer and other health problems - can be further reduced by vitamin E. This vitamin is essential for, among other things, keeping blood flowing rather than clotting at the wrong time.

"We want to know if - and how and when - vitamin E protects fish oil's fatty acids from oxidation so that HDL containing these acids can remove more cholesterol from the bloodstream," Berlin says.

Steven Crone, a 1991 graduate of Mount Hebron High School in Ellicott City, Maryland, majors in molecular and cell biology at Penn State University. But last summer his task was to help Berlin analyze blood samples from a human study.

During the 28-week study, 40 volunteers took all their meals at the Beltsville center. After week 10, they got a 15-gram daily supplement of fish oil. During the final 8 weeks, they also got a vitamin E supplement.

"We saw, from Steve's work on analyzing the samples, signs that vitamin E protected the unsaturated fatty acids better in some lipoproteins than in others," Berlin says. But, he adds. the findings aren't enough to prove vitamin E reduces heart disease risks.

To run the analyses, Crone learned to perform thin-layer chromatography and use a gas chromatograph and spectrophotometer. "That taught me not to be afraid of trying something new," Crone says. "I also learned to look at data critically, proofread, and make sure I'd done everything thoroughly. If it didn't look right, I redid it."

Another benefit of the apprentice program, says chemist Aldo Ferretti, is to expose students to ideas they may not encounter in school. "Teachers have so many demands on them," he says, "they often don't have time to show students where the frontiers are in science."

Plus, Ferretti adds, science is "hard work and sometimes you get dirty."

Glenn Flaim needed no introduction to those two ideas - having worked a few years as a bricklayer's helper. Last year, after graduating from Crossland High School in Temple Hills, Maryland, Flaim went to work at the Lipid lab. He helped Ferretti with different aspects of the fish oil study.

Cholesterol count is a well known risk indicator for heart disease, Ferretti notes, but "Glenn helped us examine how fish oil affects a more complex biochemical indicator."

That indicator is 11-dehydro-thromboxane B-2. It's excreted in the urine as a breakdown product of thromboxane, a quasi-hormonal substance produced in the blood. Excess thromboxane raises the risk of heart disease partly by constricting arteries.

While too much cholesterol is like sludge clogging a hose, excess thromboxane worsens matters by making the hose narrower.

Flaim ran analyses for B-2 in purified urine samples. For the part of the study when the volunteers got fish oil, we found a significant drop in B-2," Ferretti says. "That means the volunteers were making less thromboxane because of the fish oil. This wasn't a new finding, but it was especially meaningful because this was the largest study of its kind in humans."

He and technician Vincent Flanagan taught Flaim how to use chromatographs, mass spectrophotometers, and other laboratory tools.

Flaim, now at Prince George's County Community College in Maryland, says, "Working at ARS gave me a better basis for making the decision on whether to major in a science. Working in a lab is okay, but you might not have any results for a year. When I lay bricks, I can see results fast." Still, while he hasn't made a final decision, he's leaning toward science.

Progress can take a long time, agrees Ferretti. "Glenn should feel encouraged that he helped us add a small brick to the building of science, so it can better serve human health. And he also helped us develop a new, more specific and sensitive method for measuring the thromboxane byproduct. He was one of the first people to use it."

The method will also be used in future human studies, Ferretti adds. "We want to see the changes that fish oil and other fat sources produce in the ratio of thromboxane to its biological counterpart" - an artery-dilating quasi-hormone called prostacyclin.

"That work will be exciting, and may give us a more comprehensive view of what the body is doing than we have had before," says Ferretti.

"Science begins with curiosity," according, to Danielle Spearman, senior at LaReine High School in Suitland, Maryland.

She started out with no idea what to expect from working in a scientific lab. "I kept thinking I'd be lonely and uncomfortable." But the experience taught her differently: "You can't prejudge what a situation will be like and back away. Instead, I learned from everybody I talked to."

Her openness and determination will pay off, especially if she pursues her interest in engineering - a field with few black women today.

In a way, working with a research team was similar to something Spearman has been doing for several years. She sings alto in a choir that's performed at Constitution Hall in Washington, D.C., and many other places.

Singing, she knows from experience, calls for discipline, dedication, and hard work spanning many more hours than a concert performance. That's not unlike the long labor on a science experiment that "performs" in public as a journal report.

At ARS, Spearman helped chemist Norberta Schoene analyze results of a study conducted because an intriguing finding turned up in the fish oil experiment.

"The fish oil," Schoene says, "reduced the overall average volume of the volunteers' blood platelets, but the numbers of platelets remained the same."

Platelets, normally flat discs, swell to spheres as a first step in becoming, activated to stop bleeding. When many spheres send out spikes that interlock with each other, clumps or aggregates form to make the blood coagulate. But abnormal activation may cause unwanted coagulation. That can restrict blood flow - a common problem in diabetics and people with heart disease.

"If," she says, "fish oil reduces platelet volume but not the total platelet count, it suggests that more of the platelets stayed disc-like."

While fish oil is already known to reduce activation, platelet volume may be a more precise indicator. Schoene cautions that this possibility has to be carefully investigated. "We first need a method to measure volume that will be accurate, reliable, and reproducible," she says. "The reading varies depending on how long a sample sits and which anticoagulant is added to the sample to keep it from turning to jelly."

To help Schoene identify the best anticoagulant and timing, Spearman ran blood samples - which the scientist had drawn from laboratory rats - through a cell counter. This high-tech instrument counts and sizes the platelets.

Spearman transmitted the counter's data to a computer and used software to graph the results so Schoene could analyze them.

Armed with the findings, Schoene can now plan new studies on how dietary fats affect platelet volume in both laboratory animals and human volunteers. One day, the results could help nutritionists and physicians design more healthful diets, especially for people at higher risk of heart disease, diabetes, and other ailments.

"It took a while to believe I was being so trusted," Spearman recalls, "but I knew Dr. Schoene depended on me to make correct calculations."

For the singer-student, this trust may have wrapped some harmony around the cold staccato notes of data.

"When you work around science," Spearman muses, "you learn how many things there are to think about in this world."
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Author:De Quattro, Jim
Publication:Agricultural Research
Date:Apr 1, 1992
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