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Special Report: Managing Diabetes

More than 171 million people have this increasingly common condition. But lizard spit, new monitors and an array of other drugs and devices can help control diabetes better than ever 

Diabetes has reached virtually epidemic levels in the modern world. In 2005 the U.S. Centers for Disease Control and Prevention estimated that about 7 percent of the American population (20.9 million people) had diabetes—and 6.2 million of them were unaware of it. More than 1.5 million people over the age of 20 will be diagnosed with it in the U.S. this year. About 21 percent of those older than 60 have the disease.

Small wonder, then, given the severe complications associated with diabetes, that it continues to be the sixth leading cause of death in the U.S. And although diabetes was often called a “disease of affluence” in the past, it is now one of the fastest-rising health concerns in developing nations as well: the World Health Organization pegs the global total at more than 171 million cases.

An unfortunate catch-22 of diabetes is that although the right diet and exercise can help with its prevention and management, diabetes itself can complicate both eating and physical activity. Patients may need to pay extra attention to taking meals on a regular schedule and to monitoring how exercise dehydrates them or lowers their blood glucose. Some may fail to comply consistently with prescribed regimens that seem inconvenient or unpleasant, thereby raising their risk of complications. But thanks to leaps in science’s understanding of the disease, doctors now wield a diverse and growing arsenal of drugs and management technologies to fight the progression—and even onset—of illness. People with diabetes have more and better options than ever before for enjoying healthy, active, long lives.

Background
Diabetes is a disease in which too much of a sugar called glucose accumulates in the blood because of a breakdown in how the body makes or reacts to the hormone insulin. Insulin enables muscle, fat and other types of cells to take up and process glucose. If cells can’t burn or store glucose normally and the blood levels rise ­chronically, damage accumulates throughout the body—in the worst cases leading to blindness, amputation, kidney failure or death.

Most cases fall into one of two categories:
Type 1 diabetes (formerly known as juvenile diabetes) occurs when the body sabotages its own ability to produce insulin. A disorder of the patient’s immune system causes it to attack the insulin-making beta cells in the pancreas. Consequently, patients with type 1 diabetes need an artificial source of insulin. Although it is the most common form of diabetes in children, only 5 to 10 percent of all cases of diabetes in the U.S. are of this variety.

Type 2 diabetes, which has become increasingly prevalent during the past few decades, arises from “insulin resistance,” which causes cells, for poorly understood reasons, to stop responding properly to the hormone. At first, the pancreas can compensate by producing greater amounts of insulin. But over time, the pancreas reduces its production, making matters worse. Initially this type of diabetes may respond to diet, exercise and weight control, but later medications, and perhaps insulin, may be necessary depending on the severity of the case.

In addition, about 4 percent of all pregnant women develop gestational diabetes, a form that usually resolves itself after delivery. Diabetes can also be a rare consequence of certain genetic conditions or chemical exposures.

Symptoms, Risk Factors and Diagnosis
More than six million Americans have type 2 diabetes and don’t know it because its early symptoms can seem so harmless and vague:

  •   Frequent urination
  •   Extreme thirst and hunger
  •   Irritability
  •   Fatigue

In contrast, type 1 diabetes comes on more quickly and with more prominent symptoms, such as unexplained rapid weight loss, dehydration or a severe illness called ketoacidosis. Medical science has still not yet determined precisely why some people develop diabetes and others do not—the genetic and environmental triggers for the disease are surprisingly complex.

For example, type 1 diabetes is not simply genetic in origin, because even the identical twin of someone with diabetes, who shares the same genes, will develop the condition no more than 50 percent of the time. Some as yet unidentified factor in the environment—perhaps a virus—must therefore trigger the immune systems of genetically susceptible people to attack the beta cells in their pancreas. Other environmental factors also seem to be involved: research finds that type 1 diabetes is less common among those who were breast-fed.

For type 2 diabetes, the genetic component is greater: it tends to run more obviously in families, and the identical twin of a person with diabetes will manifest the disease up to 75 percent of the time. Yet it is also very strongly linked to weight gain and insufficient exercise. As the American Diabetes Association (ADA) notes, “[A] family history of type 2 diabetes is one of the strongest risk factors for getting the disease, but it only seems to matter in people living a Western lifestyle.” In the U.S., type 2 diabetes is also more common among African-Americans, Latinos, Asians and Native Americans.

Two ways to diagnose diabetes definitively are testing a patient’s blood with either a fasting plasma glucose (FPG) test or an oral glucose tolerance test (OGTT). The FPG measures the concentration of glucose in the blood of a person who has been fasting for 12 hours; if it is above 125 milligrams per deciliter, the patient is diabetic. The OGTT measures the subject’s blood glucose level both after a fast and two hours after consuming a glucose-rich drink; diabetes is the diagnosis if the latter reading is above 200 milligrams per deciliter. (The ADA favors the FPG because it is less expensive, faster and easier for patients.)

Prevention and Prediabetes
People do not become diabetic overnight. Almost all of those who eventually acquire type 2 diabetes move first through a
“predia­betes” state in which their blood glucose levels are elevated but not quite high enough to qualify as diabetes. (Predia­betes is also called impaired glucose ­tolerance and impaired fasting glucose, depending on the tests used to diagnose it.) Research suggests even those slightly less than diabetic blood glucose levels may do long-term damage to the body, and patients with prediabetes are at a 50 percent higher risk for heart disease and stroke. In a major clinical trial from 2002 called the Diabetes Prevention Program (DPP), roughly 11 percent of those with prediabetes became type 2 diabetics during the three years of the study.

The good news for the estimated 54 million Americans who have pre­diabetes is that many can prevent their conditions from progressing through moderate exercise and changes to diet. In fact, many of them might even be able to return their blood glucose levels to normal. The DPP found that patients who lowered their body weight by a mere 5 to 10 percent—typically just 10 to 15 pounds—through diet and moderate exercise reduced their risk of developing diabetes by 58 percent. These interventions were even more effective among patients older than 60: their risk fell by 71 percent. And it should go without saying that regular exercise and a healthy diet can help keep people from acquiring prediabetes, too.

Management and Treatment
The main goal in diabetes management is to constantly keep blood glucose levels as normal as possible. Clinical studies have shown that the rate of complications from the disease drops markedly when this standard is maintained over long periods.

But doing so is not just a matter of swallowing a pill or taking a shot. People with the condition need to steadily monitor their blood glucose levels or to anticipate changes in them and respond appropriately. To state the obvious: a sound program of diabetes management and treatment needs to be developed with a qualified health care team.

Monitoring blood glucose. All people with diabetes should periodically have a hemoglobin A1c test, which indicates the patient’s average blood glucose concentration over the preceding three months. This measurement is often the best way to see how well a treatment is going overall. Depending on his or her situation, a patient might also be monitoring daily blood glucose ­levels with a home blood tester. Typically this test involves pricking a finger (or palm or arm) with a trigger-style lancet, applying the drop of blood to a test strip and inserting it into a digital reader.

In a major technical advance, three companies have recently introduced continuous glucose-monitoring systems, which sample blood glucose levels many times over the course of the day with small radio-equipped sensors embedded under the skin [see “Monitoring: An End to Pricked Fingers,” below, and “Docs on Call,” below]. The systems can be programmed to sound an alarm if blood glucose goes too high or too low. Such units could eventually help revolutionize the treatment of type 1 diabetes in particular: linked to pumps for delivering insulin, they could be part of a “mechanical pancreas” that would both sense glucose in the blood and administer insulin accordingly.

Insulin. Until the 1920s, when type 1 was still the dominant form, a diagnosis of diabetes was virtually a death sentence. That all changed with the identification and isolation of insulin, which made it possible to treat the condition for the first time.

But making use of insulin began as a messy process. Running animal pancreases through a meat grinder to obtain insulin yielded a murky liquid with difficult-to-predict efficacy levels, which sometimes provoked allergic reactions. Because digestive enzymes destroy the insulin molecule, it cannot be taken orally: insulin had to be injected under the skin with a syringe. Moreover, delivering insulin in ways that most closely mimicked the body’s natural hormone action was a challenge.

Over the decades, however, every aspect of insulin therapy has improved:
Better insulins. Thanks to recombinant DNA technology, since 1982 the biotechnology industry has been able to mass-produce human insulin proteins by growing them in bacteria. Such insulin behaves more like the body’s own than animal proteins can and is less allergenic. All insulin sold in the U.S. is now of this human type.

Normally a pancreas releases small amounts of insulin into the circulation constantly, with bigger infusions at mealtimes. Most people who take insulin therefore use two types: a long-acting “basal” insulin administered once or twice a day and a rapid-acting “bolus” insulin before meals. In recent years, pharmaceutical companies have further reformulated the human insulins to create faster-, slower- and intermediate-working versions, with different durations of action, all in an attempt to re-create what the human body does.

Nicer needles. Insulin-dependent patients used to depend on large-bore needles that were relatively expensive and quickly went dull. Today’s syringes have extremely small gauge needles that can be surprisingly painless. Some insulins are packaged inside pen-shaped injectors, eliminating the need for drawing fluid out of a vial with a syringe. The pen contains many doses of insulin; new disposable needles are attached for each dosage. It makes injecting in public far more discreet.

Alternatives to injection. To most people, needle sticks are fundamentally unpleasant. So researchers have been trying to figure out easier ways to get insulin into the system. One step in that direction is the insulin pump, a pagerlike device that is worn continually and can be programmed to deliver both basal and bolus infusions through a catheter inserted under the skin. For some patients, this system is more discreet and effective than syringe injections can be. Still, pump supplies are more expensive, and care must be taken during exercise that the pump is not dislodged or damaged.

Another alternative is inhalable insulin. Pfizer introduced a version (Exubera) in 2006, but withdrew it from the market last fall, perhaps because of a somewhat unwieldy apparatus (the “insulin bong,” as some have dubbed it), the additional training required to use the device and lingering questions about long-term pulmonary effects. Other delivery methods are still under investigation, including a nasal spray, a self-contained implantable pump and a transdermal patch that uses electric current to move insulin across the skin barrier.

The ideal would be an effective oral version of insulin that could avoid destruction in the digestive tract. A number of companies are working on developing oral insulins, and Generex Biotechnology has an oral insulin spray approved for sale in Ecuador; however, similar products may be years away from proving safe and effective enough to satisfy the U.S. Food and Drug Administration.

Other Medications
Most people with diabetes do not need to take insulin, because their bodies still make some. Instead they take medications that can help them produce more insulin or use it better. Until recently, these
oral meds fell into five categories: alpha glucosidase inhibitors (Precose, Glycet), metformin, meglitinides (Starlix, Prandin), sulfonylureas, and thiazolidinediones (Avandia and Actos, which have been in the headlines because of persistent concerns over their cardiovascular effects). A newer class is the DPP-4 inhibitors (Januvia is the only drug of this type available so far), which help to maintain levels of GLP-1, an intestinal hormone that promotes insulin production.

Excitement also surrounds two other new classes of drugs: incretin mimetic agents (Byetta, derived from the saliva of the Gila monster, is the only one currently on the market) and amylin analogues (Symlin is the first to be approved). Incretins are hormones that the digestive tract releases in response to carbohydrates and fats and that tell the pancreas to secrete extra insulin. Amylin is another hormone produced by the pancreas, and it helps to depress blood glucose.

Like insulin, both incretin mimetics and amylin analogues must be injected. They both have a beneficial side effect, however: they slow the emptying of the stomach. As a result, people feel full sooner, eat less and often lose weight on these drugs, which in itself can improve their diabetes.

Extreme Techniques
For some patients, dramatic measures may be called for.
Gastric bypass or reduction surgery, which shrinks the space in the stomach for food, can sometimes almost eliminate type 2 diabetes in morbidly obese patients (the surgery carries its own risks, however). For a few people with type 1 diabetes, one option might be a pancreas transplant, to replace the insulin-making beta cells they have lost. But this surgery, too, can be hazardous, and few pancreases are available for transplantation. Moreover, to prevent the patient’s immune system from rejecting the new pancreas, he or she would need to take immunosuppressive drugs for life, which can also be dangerous.

A potentially safer (and less expensive) choice could someday be the experimental procedure of transplanting just the pancreatic islet clusters that contain the beta cells. Such implants would involve less trauma than replacing an entire pancreas, and it might be possible to encase the grafted cells in packaging that would protect them from the immune system. Researchers are also working on using highly versatile stem cells, which can give rise to new tissues, to replace lost beta cells. The early results are guardedly positive, but it will be years, if ever, before such a technique becomes widely available.

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The Skinny on the Environment

The very structure of our communities may predispose us to inactivity and obesity. Now researchers are remodeling cities for healthier kids 

 
Well-planned communities balance natural and artificial spaces.

When Susan Handy moved to Davis, Calif., in 2002, she immediately bought a commuting vehicle: a wheeled trailer, for toting her kids behind her bike. Handy, an environmental policy analyst at the University of California, and her husband frequently pedal to work, with two preschoolers in tow. Among locals, their commute is common. Fifty miles of bike lanes ribbon Davis, which is only about 10.5 square miles in area. Handy calls Davis “a small town that really works.”

City planners, health researchers and local leaders want more U.S. communities to “really work”—and to that end, they have begun retrofitting the country, from Atlanta to Sacramento. Inspired by a new urbanism that celebrates neighborhoods and alarmed by health problems—particularly childhood obesity—these trailblazers are building paths, sidewalks and other architectural features while promoting policies and behaviors that get people moving.

They have plenty to do. America’s metropolitan landscape is a fractured network of residential and industrial buildings, haphazardly decorated with green space. To get around in their “built environment,” or human-made surroundings, members of the average American household collectively logged more than 32,000 miles of car travel in 2001. According to National Household Travel Survey data, only 15 percent of children in the U.S. walk or bike to school—a 35 percent drop from three decades ago. At the same time, kids now spend an average of 44 hours a week sitting in front of a television, computer screen or other video monitor, according to a 2005 Kaiser Family Foundation study. Over the past five years, the study concludes, this “Generation M” (for media) has increased its total exposure by more than an hour each day, mostly by multitasking with different forms at once.

“Our built environment is a recipe for health problems, from obesity to asthma to depression,” says Richard Jackson, an adjunct professor of environmental health at the University of California, Berkeley. “Poor urban design has a distinct impact.” Childhood obesity, in particular, has become epidemic. Nearly a fifth of all children and adolescents in the U.S.—more than 12 million—are now overweight, according to the CDC’s National Center for Health Statistics. Can the U.S. redesign itself for a healthier future?

Trails to Fitness
Today’s built environments reflect decades of urban planning with a few consistent themes—cars and zoning, among them. The advent of America’s car culture in the 1950s inspired suburbs that sprawl, Handy points out. Reinforcing this trend, urban zoning requirements have frequently separated industrial or commercial settings and residential neighborhoods—partly in the interest of public health, to ensure that most homeowners do not live near polluting factories.

But this blueprint currently looks less benign. Pollution from nonfactory sources, such as smog from car tailpipes and lawn equipment, still fouls the air and contributes to asthma. Idle hours in the car spent traveling between residential and commercial destinations add up to inactivity. Even those who prefer to bike or walk often confront crowded roads and hectic intersections.

Rather than simply accepting this modern metropolis, early built-environment mavericks pushed for local change. On a sunny day in 1991, for instance, three cycling buddies in sprawling Atlanta together lamented the city’s polluted air and lack of bike trails. Then they got busy. The trio created the PATH foundation, a nonprofit whose mission is to develop a system of linked trails throughout metropolitan Atlanta.

Sixteen years later the PATH foundation has built 110 miles of trails in and around the city, through wetlands and nature preserves, along highways and across neighborhoods. The longest trail, dubbed the Silver Comet, stretches 57 miles from Atlanta to the Alabama state line. Built with a plan that combines public and private financing, all the trails are 12 feet wide, made of concrete and lined with maintained green space. PATH’s executive director, Ed McBrayer, calls the trails “linear parks.”

The Ultimate Blood Test

A pricey way to determine health risks: 250 tests at once

 


As the dizziness began to fade and the nausea to subside, I kept thinking how two tablespoons did not sound like a lot of blood. During regular checkups, my physician draws only about half that amount. I suppose I might have guessed, especially after a 12-hour fast, I would sicken when my blood pressure and glucose levels dipped—I’m a terrible blood donor in that regard.

The nurse who drew my blood helpfully looked around my office for a sweet drink. “Do you have any soda or juice?” she asked. But the only thing I had was a can of Diet Coke. Which in a way is ironic: I used to drink regular Coke but switched to the sugar-free form after blood tests revealed that my triglycerides were too high.

Momentary ill feelings, though, were an acceptable physical price for 250 blood tests done at once—I was told that running them separately with conventional means would require a liter of blood. (Imagine how dizzy and nauseated I’d feel then.) So how could I not roll up my sleeve for Biophysical Corporation? The Austin, Tex.–based company promised to use the blood to screen for presymptomatic cancers, potential immune disorders, latent infections, undetected hormonal imbalances and unrecognized nutritional deficiencies. It seemed to mark a step toward that Star Trek future in which Dr. McCoy waves around a device shaped like a saltshaker to determine a person’s medical secrets. (“Heartbeat is all wrong. Body temperature is … Jim, this man is a Klingon!”)

The Biophysical250 assessment, as the firm calls it, is more than just a battery of tests. It includes a medical-history interview; a personal visit to the home or office for the blood draw (I should have picked my home, where I actually keep sugar); and a follow-up physician consultation. All this attention does not come cheap. It costs $3,400 and is not covered by health insurance. The company states that doing each test individually would cost 10 times more, so the Biophysical250 is a bargain by comparison. Still, you either need some disposable income or must be so indispensable to your employers that they will pay for it. I don’t fall into either category. But because I was reviewing its product, Biophysical agreed to conduct the test on me for free.

The analysis focuses on blood biomarkers, which are chemicals whose presence or amount may indicate abnormal processes or reactions in the body. Among the most familiar are cardiovascular ones: high- and low-density lipoproteins (HDL and LDL, the good and bad cholesterols) and triglycerides.

Checking 250 biomarkers at once might seem like overkill. A routine exam screens for two or three dozen. Looking at one biomarker in isolation, however, is usually not especially informative—for instance, the ratio of LDL to HDL is more important than either alone. The Biophysical250 takes it much further: to assess the risk for heart disease and stroke, the firm analyzes 33 biomarkers.

Examining several biomarkers together improves the odds of finding problems early, especially malignancies. Blood tests for cancers have been problematic, because healthy people may produce the same kinds and amounts of the biomarkers that cancer patients do. Moreover, the chemicals do not always show up in cancer patients, and they may result from unrelated conditions. The Biophysical250 screens for about four dozen blood chemicals tied to cancerous activity in general to increase the odds of detecting disease before symptoms appear.

For example, Biophysical points to ovarian cancer, which is usually diagnosed too late. Cancer antigen 125, the most commonly measured marker for the disease, shows up in only half of patients in stage 1, when treatment is most likely to succeed. The Biophysical250 tries to boost the chance of early detection by measuring other, biologically independent compounds, such as vascular endothelial growth factor, interleukin-6 and monocyte chemoattractant protein.

Testosterone's Bad Rep

Hormones don't necessarily make men violent, but they do cause them to seek social dominance 


Professional wrestler Chris Benoit’s powerful build and muscular grappling maneuvers helped to make him a crowd favorite and propelled him to a world heavyweight championship in 2004. No one was prepared for the shocking turn this past June when he killed his wife and son, then hanged himself in their home near Atlanta. The subsequent announcement by the state medical examiner’s office that Benoit’s body showed he had been taking injections of testosterone (along with an antianxiety drug and a painkiller) seemed all too predictable, given how often anabolic steroids such as testosterone have been linked to violent behavior.

And yet the official findings might still have offered one surprise: according to medical examiner Kris ­Sperry, there was no clear evidence that the steroids played a part in the murders. Benoit’s levels of testosterone were 10 times normal, but as Sperry was quoted as pointing out, “An elevation of that ratio does not translate into something abnormal in a person’s thought process or behavior.”

It’s commonly assumed that testosterone, that stereotypically male hormone, is intimately tied to violence. The evidence is all around us: weight lifters who overdose on anabolic steroids experience “roid rage,” and castration—the removal of the main source of testosterone—has been a staple of animal husbandry for centuries.

But what is the nature of that relationship? If you give a normal man a shot of testosterone, will he turn into the Incredible Hulk? And do violent men have higher levels of testosterone than their more docile peers?

Historically, scientists had assumed the answer was yes, but the truth has proved more complex. “Researchers expected an increase in testosterone levels to inevitably lead to more aggression, and this didn’t reliably occur,” says Frank T. McAndrew, a professor of psychology at Knox College in Galesburg, Ill. Indeed, recent research about testosterone and aggression finds only a weak connection between the two. And when aggression is more narrowly defined as simple physical violence, the connection all but disappears.

“What psychologists and psychiatrists say is that testosterone has a facilitative effect on aggression,” comments Melvin J. Konner, an anthropologist at Emory University and author of The Tangled Wing: Biological Constraints on the Human Spirit (Owl, 2003). “You don’t have a push-pull, click-click relationship where you inject testosterone and get aggressiveness.”

Instead what emerges from experiments with surgical and medical castration is a more complex pattern of cause and effect. Testosterone may be necessary for enabling violent behavior, but it is not, on its own, sufficient. In that sense, testosterone is less a perpetrator and more an accomplice—one that is sometimes not too far from the scene of the crime.

In both men’s and women’s prisons, for example, the most violent inmates have higher levels of testosterone than their less violent peers. Yet scientists hypothesize that this violence is just one manifestation of the much more biologically and reproductively salient goal of dominance.

“It has been suggested that the antisocial behaviors related to high testosterone are a function of the manner by which dominance is maintained in these groups,” says psychologist Robert Josephs of the University of Texas at Austin. In other words, if researchers were to study other groups of folks—say, the rich and famous—they might discover that testosterone is connected not to violence but to the person who drives the biggest SUV or has the nicest lawn. As Josephs puts it: “Slipping a shiv into your neighbor’s back might play in the penitentiary, but it probably won’t earn you any status points in Grosse Pointe.”

The late psychologist James M. Dabbs made a career out of conducting studies connecting testosterone to every kind of lifestyle imaginable. In his book Heroes, Rogues and Lovers (McGraw-Hill, 2001), co-authored with Mary Godwin Dabbs, he notes that athletes, actors, blue-collar workers and con artists tend to have higher levels of testosterone than clerks, intellectuals and administrators.

Biodiesel Takes to the Sky

An unmodified Czechoslovakian jet flew burning nothing but cooking oil 

biojet-one 
FRYING FUEL: BioJet 1 flew for 37 minutes with only pure cooking oil in its engines.

Biodiesel may not become the airplane fuel of the future but it did prove effective enough to recently power a 1968 L-29 Czechoslovakian jet—dubbed BioJet 1—up to 17,000 feet (5,180 meters) over 37 minutes. A three minute, 15-second test the day before was the world's first flight entirely fueled by cooking oil.

"She flew and she flew just fine," says physicist Rudi Wiedemann, president and CEO of Biodiesel Solutions, Inc., whose company provided the fuel for the historic October flight: fresh canola oil refined into biodiesel. "We wanted to show that it was doable by just going out and doing it."

Specifically, Doug Rodante, president of Green Flight International (a company in Florida that promotes alternative aviation fuels), and chief test pilot Carol Sugars, a senior pilot with the United Parcel Service (UPS), conducted extensive fuel tests on the ground, beginning with a 20 percent blend of biodiesel and normal jet fuel (kerosene known as Jet A) and progressing to 100 percent biodiesel (B100) as their confidence increased.

Revolutions per minute in the engine on B100 were at 98 percent, Rodante notes. "We didn't get full power, but we got an acceptable amount" he says. "It was a nonissue in climb performance and time to altitude."

The L-29 jet (acquired from the Ukrainian military) is one of the few planes capable of burning biodiesel at present, thanks to a built-in fuel warming system. Biodiesel can gel at cooler temperatures, such as those experienced on a winter's day or at high altitude. "Jet fuel and biofuel mix is something that is easily done. I don't believe 100 percent biofuel is the answer," Rodante says. "We can implement a 20 percent mix with no modifications in other aircraft."

Such a blend would offer significant environmental benefit—most notably reduced emissions of carbon dioxide, the most common greenhouse gas. "As little as 20 percent biodiesel in petroleum diesel fuel will reduce carbon emissions by 50 percent," Wiedemann says. Airplanes emit roughly 12 percent of the man-made greenhouse gas emissions from transportation, but they are among the fastest growing sources and, potentially, the most damaging because of their release higher in the atmosphere. And the U.S. Air Force has been evaluating alternative fuels, including biofuels from animal fats, going so far as to certify the B-52 bomber to burn such synthetic fuels.

The Green Flight team is currently evaluating the exact emissions of the biodiesel burning as well as how it affected the various seals and rings in the L-29's jet engines. Until the latter testing is wrapped up and Biojet 1's safety is confirmed, the Federal Aviation Administration has grounded the plane. But Rodante says the evaluations could be completed within the next few weeks, after which he plans to fly the experimental jet from Reno, Nev., to Orlando, Fla.—the first transcontinental biodiesel flight, in eight stops. And, eventually, he hopes to fly a similarly fuelled plane around the world. "Aviation emissions are something that needs to be addressed," he says. "We're not moving fast enough."

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