Dear Doctor: Please inform your readers about polymyalgia rheumatica. I thought I was experiencing arthritis, until my doctor informed me otherwise.

Dear Reader: Polymyalgia rheumatica is a common disorder that generally occurs in adults over the age of 50, with peak incidence occurring between the ages of 70 to 80. PMR causes stiffness and aching in both shoulders and both sides of the neck; it also affects the hips and lower back. The symptoms are worse first thing in the morning, and ease over the course of the day.

The condition is two to three times more common in women than in men and is also more prevalent among people of northern European ancestry. In fact, among those over 50 in one Minnesota county, the prevalence of PMR is 1 in 140 people. The rate appears to be lower in parts of the country with greater African-, Asian- and Latin-American populations.

The causes of PMR are unknown. It's possible that an environmental factor leads to the production of inflammatory molecules. Note, however, that although the word polymyalgia implies muscle inflammation, no muscle damage has been linked to the condition. What does appear to happen is inflammation of the tendons, bursa and joints in the hips and shoulders.

This inflammation leads to severe stiffness and pain. The stiffness often occurs suddenly, causing significant movement problems. An affected person can have difficulty getting out of a chair or putting on socks or a shirt. Half the time, the symptoms occur beyond the hips and shoulders, such as the wrists, hands and the knees. Often, patients with PMR also experience fatigue, weight loss and low-grade fever.

PMR causes a decreased range of motion in the shoulders and hips and sometimes swelling at the wrist and hands. A doctor's diagnosis is solidified with blood tests that show elevations in the inflammatory markers, Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Moreover, people with PMR may have mild anemia, which may be a reason for the fatigue.

Treatment consists of medication to decrease the inflammation, often with a low dose of the steroid prednisone. In fact, a significant rapid improvement of symptoms with a 15- to 20-milligram dose of prednisone helps to differentiate PMR from other disorders.

Because long-term use of oral steroids like prednisone can increase the risk of osteoporosis, high blood pressure and elevations of blood sugar, the medication should be tapered off after a while. This must be done slowly, however, so that the symptoms of PMR don't return. In total, oral steroids need to be continued from six months to potentially more than two years. Other therapies that suppress the immune system could also be used, but they have not shown the same benefits.

On a last note, people with PMR are at increased risk of having giant cell arteritis, which causes headaches and a transient or irreversible loss of vision in one eye. If you have PMR and notice these symptoms, seek medical attention immediately.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I know I need to eat more vegetables, but because I have dentures, I can't chew them well enough to swallow easily. I have particular problems with celery, lettuce, oranges and tomato skins. If I were to "masticate" them in a food processor, would I still get the benefits, or would the processor blade destroy too many cells?

Dear Reader: We see you're familiar with two indisputable facts when it comes to living with dentures: First, the way they function is different from our original teeth. Dentures rely on a seal to stay in place, so you have to be careful about the types of foods you eat. Texture (think nuts or steak or seeded breads) and the angle of attack (like an apple or corn on the cob) can wreak havoc on both the seal that keeps the dentures in place, and sometimes the dentures themselves. Second, these challenges don't have to be a barrier to the foods you want to eat. As your question illustrates, a bit of creative problem solving can add to the diversity of the foods in your diet.

While there's a certain logic to the idea that using a food processor to chop or mince or emulsify a food can adversely affect its nutritional content, the good news is that's not the case. What appliances like food processors and blenders do first and foremost is to alter a food's texture and, of course, its appearance. And let's agree that we're not talking about juicing here. That's the process in which the liquid content of a food is extracted and the resulting pulp, the food's fiber content, is left behind. That's an entirely different process with outcomes that merit a separate discussion. (Drop us a line if you're interested.)

Digestion begins the minute food enters the mouth. Teeth pulverize the bite into smaller pieces and particles and mix it with saliva, all of which jump-starts the process of dismantling the food on a chemical level. The lion's share of the work of breaking down the bonds between food molecules takes place after you swallow, carried out by powerful enzymes in the stomach, and trillions of friendly bacteria in the intestines. What you're proposing is to get a head start on the chewing process with the help of a food processor. Depending on the blade you use, you can slice, chop, pulverize or puree.

The act of slicing, chopping or pureeing food doesn't change its nutritional value. However, once a food is broken down, the nutritional clock does start ticking. That's because a wide range of nutrients found in vegetables and fruit are sensitive to air and light, as well as to heat. When you put an item through the food processor, it's a good idea to eat it the same day. Wrap any leftovers tightly and refrigerate.

In general, remember to chew on both sides of your mouth when you're living with dentures. Dental adhesives can help when a saliva seal proves inadequate. As you've shown, with preparation and imagination, dentures needn't be an impediment to a balanced and interesting diet.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Could you tell me about the causes, treatment and remission rates for Burkitt lymphoma?

Dear Reader: Burkitt lymphoma is a highly aggressive, rapidly growing type of B cell lymphoma. It's caused by an alteration to a gene involved with cell division and cell death. The alteration of this gene causes B cell lymphocytes (a type of white blood cell) to divide quickly and repeatedly, creating multiple abnormal cells.

There are three types of Burkitt lymphoma, and the likelihood of each one depends on your geographic region and your immune status. In Africa, the incidence of Burkitt lymphoma is 50 times higher than in the United States, with the disease there caused largely by chronic Epstein-Barr virus infection. In this type of Burkitt lymphoma, the peak incidence of infection is between the ages of 4 and 7. Often, the disease is initially found in the bones of the face or jaw; from there it can spread to other parts of the body.

The most common type of Burkitt lymphoma in the United States is much rarer -- about three cases per million people per year -- and the peak incidence is about 11 years of age, with the majority of cases occurring in people younger than 35.

The third type of Burkitt lymphoma occurs in people with a suppressed immune system, usually due to HIV infection. In these cases, the suppression of the immune system causes viruses, like Epstein-Barr, to exert genetic changes on B cells that lead to lymphoma.

Because Burkitt lymphoma is a rapidly growing cancer, chemotherapy works well against it, and multiple drugs are available to stop its growth and destroy the rapidly growing B cells. In fact, because drugs are so effective, radiation and surgery are not generally recommended. Of note, many chemotherapy regimens now include the medication Rituxan, often used for rheumatoid arthritis, because of its ability to attack B lymphocytes. Because Burkitt lymphoma can often make its way to the brain, most chemotherapy treatments are also given via the cerebrospinal fluid by way of a lumbar puncture.

Chemotherapy is not without its side effects. Part of the difficulty in older adults, especially those over the age of 60, is the ability to tolerate these side effects. They include bone marrow suppression, in which the numbers of red and white blood cells and platelets drop dramatically. The drop in the white blood cells can make a patient more susceptible to severe bacterial infections. Chemotherapy can also lead to toxicity of the heart and the nerves of the body.

As for survival rates, those depend on the regimen of chemotherapy and the age of the patient. A study from Germany found that people ages 15 to 25 had a five-year survival rate of 90 percent; the rate decreased to 84 percent in people ages 26 to 55, and to 62 percent in those over 55.

You didn't say whether you or someone you know is being treated for Burkitt lymphoma, but, if so, I hope this limited review has been helpful.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)