(MUSIC)

VOICE ONE:

This is Steve Ember.

VOICE TWO:

And this is Bob Doughty with Science in the News, a VOA SpecialEnglish program about recent developments in Science. Today, we tellabout the disease diabetes.

(MUSIC)

VOICE ONE:

The World Health Organizationestimates that as many as one-hundred-twenty-million people have thedisease diabetes. Diabetes is the name for several diseases with onething in common: there is too much glucose, or sugar, in the blood.The disease develops when the body does not produce enough insulinor produces no insulin. Or the disease develops when the body cannotuse insulin.

Insulin is a hormone that is necessary to change sugar,carbohydrates and other food into energy. In healthy people, thebody changes food into a sugar, called glucose. Glucose is thesource of fuel for the body. When food is changed into glucose, itenters the bloodstream and is taken to all parts of the body to feedmuscles, organs, and tissue.

VOICE TWO:

When the body senses that there is too much glucose in the blood,it sends a signal to the pancreas. The pancreas is the organ thatproduces insulin. The pancreas sends insulin into the bloodstream.The insulin lowers the level of blood sugar by letting it entercells. Insulin helps muscles, organs and tissues take glucose andchange it into energy.

That is how the body operates normally, in most people. Diabetesis present when too much glucose remains in the bloodstream and doesnot enter cells. If the amount of glucose in the blood remains toohigh, the body begins showing signs of diabetes. Over time, thedisease can cause blindness, kidney disease, and nerve damage. Highglucose levels in the blood also can lead to strokes and heartdisease. Blood circulation also is affected, especially in the legs.Often, victims of diabetes must have a foot or even a leg removedbecause of blood circulation problems linked to the disease.

(MUSIC)

VOICE ONE:

There are two main kinds of diabetes, Type One and Type Two.Between five and ten percent of those suffering from diabetes haveType One. It usually begins before the age of thirty in people whoare thin.

It is most commonly found in children under the age of sixteen.It is caused by the body's defense system. The bodies of Type Onediabetes victims produce a substance that attacks and kills somecells in the pancreas, blocking the production of insulin. Thesecells are called islet cells. Scientists are not sure why thishappens. They believe there may be a number of causes.

They include viruses, the presence of insect-killing pesticidesin the environment or molecules known as free radicals. Freeradicals are produced as part of normal chemical processes in thebody. In people with diabetes, too many of these free radicals arepresent in the body. Scientists are not sure which of these causesis the most important to the development of Type One Diabetes.

VOICE TWO:

People suffering from Type One diabetes must carefully controltheir diets. And they must exercise often. People with this kind ofdiabetes almost always require insulin injections. Patients mustalways know their blood sugar levels. When the level of glucose inthe blood is too high, they must inject insulin into their bodies toreduce the amount of glucose. The patients must inject insulin everyday, often several times a day. In most developed countries, insulinis easy to get and does not cost much money. However, doctorsbelieve that these injections can cause long-term problems. Theybelieve that the injections cause levels of glucose to change often.

Scientists believe that many quick changes in glucose levels can,over time, result in damage to the body. This damage can beblindness, kidney failure, heart disease, or poor blood flow in thebody.

VOICE ONE:

Type One Diabetes also is known asjuvenile onset diabetes, because it usually starts in children oryoung people. Scientists believe it is the form of the disease thatthey will most likely be able to cure some day. Among the treatmentsbeing studied is a vaccine to prevent the disease. A vaccine isinjected into the body or taken by mouth in the form of a pill.

Another possible treatment for Type One Diabetes is placing newislet cells into the pancreas to help it make insulin. Doctors havebeen transplanting islet cells into diabetes patients for severalyears. However, these healthy islet cells have failed to permanentlyreplace the need for insulin injections.

Scientists also are studying special cells called stem cells totreat the disease. Stem cells develop into all the different kindsof cells in the body. Scientists believe that stem cells from unbornbabies could be used to treat diabetes and other diseases. However,it would be a long time before such treatment is possible.

VOICE TWO:

While some scientists continue to seek ways to cure Type OneDiabetes, others are searching for easier ways to get insulin intothe body. New devices are being developed that could replaceinjections. One device being tested is an inhaler.

This device would permit patients to breathe insulin into theirbodies. The insulin is in the form of a powder, like dust. When theinsulin reaches the lungs, it quickly moves into the bloodstream toreduce glucose levels.

(MUSIC)

VOICE ONE:

Type Two Diabetes generally is found in people more than fortyyears old. Most of these people are too fat. Their bodies can notproduce enough insulin to reduce the levels of glucose in theirblood. Or, their bodies do not react correctly to the action ofinsulin.

Type Two Diabetes is more complex than Type One. Experts say TypeTwo Diabetes is really a group of diseases, with many possiblecauses. Scientists see little hope in developing a cure for thiskind of diabetes. Instead, they are searching for better ways tocontrol it. Many people suffering from the disease can control itwith exercise and by carefully controlling their diet. Also, many ofthem do not need to inject insulin into their bodies. Type TwoDiabetes is sometimes called non-insulin dependent. Still, patientsoften need drugs to treat the disease.

VOICE TWO:

There are a number of drugs that can be used. However, many ofthem can cause other problems. One of the drugs is calledsulfonylurea. It has been used for many years to help the pancreasmake more insulin. But after several years, the drug loses itseffects on the pancreas. Also, it can cause patients to gain weight.

The drug metformin appears to be more effective. It lowers theamounts of glucose in the blood. It does this by helping the bodymake better use of its own natural insulin. It does not cause weightgain. However, metformin can be dangerous for people with damagedkidneys. It should not be used by people who drink large amounts ofalcohol, or those with kidney, liver or heart problems.

VOICE ONE:

Genes seem to be more important in the development of Type TwoDiabetes than in Type One. About ninety percent of those with TypeTwo Diabetes have parents and ancestors who also had the disease. Inrecent years, scientists have found several genes that may be linkedto Type Two Diabetes. Some of these genes also are linked to extremeoverweight, known as obesity. About eighty to ninety percent ofpeople with Type Two Diabetes are obese. Often doctors do notdiscover that patients have diabetes until one of the disease'sserious results is found. For example, a doctor examines a patientsuffering several health problems.

The doctor carries out tests and finds the problems are theresults of poor kidney performance. Tests then show the patient issuffering from diabetes, which can cause kidney problems and evenfailure.

VOICE TWO:

Although great progress has been made in the treatment ofdiabetes, it is still widespread and threatens the health ofmillions of people. Scientists hope that their research will lead toa cure for Type One Diabetes. And they hope they can find new waysto improve treatment of Type Two Diabetes. In future programs wewill discuss new developments in diabetes research as they arereported.

(MUSIC)

VOICE ONE:

This Science in the News program was written by Oliver Chanler.This is Steve Ember.

VOICE TWO:

And this is Bob Doughty. Join us again next week for more newsabout science in Special English on the Voice of America.