Dear Doctor: It seems like every time I turn on the TV, there’s a commercial that talks about mesothelioma. What is it, and how do people get it?

Dear Reader: Mesothelioma is a rare, aggressive and often fatal form of cancer that arises in the mesothelial cells. These are specialized cells that form a thin membrane known as the mesothelium. It covers the majority of internal organs and lines several internal cavities, including in the chest and abdomen. Its main job is to provide a slippery protective surface so when tissues come into contact, they slide and glide rather than adhere. Depending on their specific location, mesothelial cells also secrete fluids, help with fluid transport, and play a role in immune function, inflammation control and tissue repair.

The main cause of mesothelioma is exposure to asbestos, which is a generic term for certain fibrous minerals that can be spun into strong fireproof thread. Awareness of the health hazards of asbestos dates back to 1924, but it took a series of increasingly restrictive laws in the 1970s for it to finally fall out of widespread use. At that time, it became clear that even light or intermittent exposure to asbestos, whether in buildings, products or manufacturing, was risky.

Today, past asbestos exposure, much of it occupational, accounts for up to 80% of all cases of malignant mesothelioma. There is evidence that family members of people who were regularly exposed to asbestos may also have increased risk of developing mesothelioma. The disease has also been linked to a specific X-ray process used in the early-to-mid 20th century, and family history is suspected to play a role in risk.

One of the many challenges of malignant mesothelioma is that it develops decades -- in some cases up to 40 years -- after asbestos exposure. Another is that symptoms often become apparent only when the disease is advanced.

The majority of cases, up to 85%, arise in the tissues of the pleura, which is the two-layered membrane that surrounds each lung. Symptoms can include chest pain, shortness of breath and chronic cough. Some people may develop a mass in the chest wall or areas of lumpy tissue beneath the skin on the chest. For disease located in the membrane around the stomach, abdominal pain, nausea, vomiting, diarrhea, unexplained weight loss and abnormal fluid accumulation can occur. When the disease affects the membrane around the heart, which is rare, symptoms can include heart arrhythmias, chest pain, difficulty breathing and low blood pressure. The disease can also cause general weakness and exhaustion, as well as night sweats.

Treatment, which includes surgery, radiation and chemotherapy, depends on the age and health of the patient, and at what stage the disease has been diagnosed. Some patients find that alternative treatments, such as acupuncture, breath training, and relaxation and mindfulness exercises can help them to cope with breathlessness. In recent years, targeted therapies, which use drugs and other substances to directly attack cancer cells, have begun to show promise. Clinical trials for new and effective treatments are ongoing.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: This year for the kids’ summer vacation, we’re renting a cabin up in the mountains. My question is, what kind of a first-aid kit should I put together? We will be there a week. We have three very busy boys, who are 8, 11 and 13, and a 4-year-old girl.

Dear Reader: It’s a great idea to pack a first-aid kit whenever you travel. And with four active children running around in an unfamiliar home and in the great outdoors for a week, it’s important to be prepared for a range of emergencies.

Pre-packaged kits are available for sale, or you can easily put together a kit tailored to the needs of your family. Use a waterproof container large enough to store everything you’ll need, and make a checklist to keep things organized. It’s also helpful to get local medical information from the landlord, including the location and contact information for the nearest pharmacy and urgent care center.

As for what to pack, start with any prescription medications or products your family uses. Bring enough for the trip, plus a few extra days in case plans change. Pack prescription meds in their original containers, which include the patient’s name, dosage instructions and information about refills. If you’ve got spares of prescription glasses, bring those along, too, just in case. If someone in the family uses a hearing aid, don’t forget extra batteries. If someone in the family has a chronic condition, such as diabetes or a serious allergy, consider a medical alert bracelet.

You’ll most likely be dealing with a range of minor medical situations. These include sunburn, insect bites, rashes, scrapes, cuts, sprains, upset stomachs, nausea, headaches, coughs and colds, and diarrhea. That means packing acetaminophen, ibuprofen or aspirin for pain and inflammation; antihistamines for anyone with an allergy; over-the-counter meds for nausea and motion sickness (this last one you might want to keep at the ready while driving); and also antacids for too-adventurous eating. Just in case, bring cold and flu meds for both children and adults.

For wound care, you’ll need an assortment of adhesive bandages, as well as antibiotic ointment for cuts, scrapes and burns. Elastic wraps, plus safety pins or other closures, will help with ankle, wrist and knee sprains. Hopefully, you won’t need them, but gauze rolls and 2- and 4-inch pads (plus adhesive tape to secure them) will take care of larger injuries. You’ll want hydrogen peroxide to clean all sizes of wounds.

In the lotion category, you’ll want to bring plenty of sunscreen, calamine lotion for run-ins with poison oak or poison ivy, hydrocortisone cream to deal with the itch from rashes, and aloe vera gel to soothe a sunburn. You’ll never regret packing bug spray, but, again, be sure to get products that are appropriate for both children and adults.

Useful tools include tweezers for splinters and bee stings, round-tipped scissors for cutting gauze and bandages to size, a thermometer, and antiseptic wipes to keep in a pocket or backpack. If anyone in the family has a severe allergy, you’ll need an EpiPen or other type of epinephrine auto-injector.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Our dad is a meat-and-potatoes guy who always skips the vegetables. But he’s crazy about his grandkids and wants to see them grow up. I just read about a study where people who ate vegetables live longer. Can you tell us about it? It might help persuade our dad.

Dear Reader: The links between improved health and a diet rich in fresh vegetables, leafy greens and fruit are quite strong. Numerous studies over the course of decades continue to reveal an array of health benefits. These include improved blood pressure and blood lipid levels; lower risk of heart disease and certain cancers; better blood glucose control; and improved gut health. Now, a team of researchers from the Harvard School of Public Health in Boston has added longevity to that impressive list.

The new study you’re asking about appeared in March in the journal Circulation. It took the veggies-are-good health claims a step further by getting specific about how many daily servings give you a better shot at a longer life. The authors found a connection between eating five servings of vegetables and fruits per day and a longer life span.

To reach that conclusion, researchers analyzed health and behavioral data from two different decadeslong health studies. They selected 66,719 women from the Nurses’ Health Study, which is a collection of 30 years of information about lifestyle factors, behaviors and personal characteristics, and the incidence of more than 30 diseases during the course of the research. They also used 28 years of data from the all-male Health Professionals Follow-up Study, from which they selected 42,016 men. To be included in this new research, each participant had to have been free from diabetes, cardiovascular disease and cancer at the start of their respective studies. They also had to have been diligent in reporting their dietary intake. Any significant gaps in that reporting disqualified them from being included in the new study.

Once the researchers crunched the numbers, they found the optimal consumption to be three servings of vegetables and two servings of fruit per day. The groups who reported eating those amounts had a reduced risk of death from any cause -- 13% less -- than those who ate two or fewer servings. The reduced risk of death from heart disease was 10%, and the risk of death from a respiratory illness was 35% lower. While eating more than those five servings was fine, it wasn’t associated with additional longevity. And apologies to you potato and fruit juice lovers, but these foods were not associated with the same health benefits.

So how do you measure servings? A small to medium-sized fruit -- such as an apple, peach or a pear -- is considered a single serving. If you’re eating berries or melon, it’s 1 cup. A serving of cooked vegetables is 1/2 cup, and for fresh leafy greens, it’s 1 cup.

We hope that this newest addition to the veggies-are-good canon of research helps you in your quest to get more fresh foods on your dad’s plate.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)