GOOD NEWS MEDICINE

By Pam Eastlick

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

Well, the medical file is overflowing and I’ve decided to feature only good news. The global warming file is also filling up and that one only has bad news, so this week let’s go take a positive look at what ails us.

I know several people who have really atrocious teeth. In some cases, it’s because they can’t afford to go to the dentist, but in many cases, money has nothing to do with it. It’s the awful nightmares of the dentist chair that they retain from their childhood.

Unfortunately, you’ll never convince them that dentistry has changed. No more spitting into the porcelain bowl, no more pain. Of course, the drill can still send vibrations down your spine, but at least they don’t hurt.

The one thing that still hurts is the needle to administer the anesthesia that keeps everything else from hurting and the first good news is that that may too, be a thing of the past.

LOOK MA NO CAVITIES!

Still afraid of the needle? A new discovery may just replace that needle for many procedures. Researchers are reporting that a common local anesthetic, when administered into the nose as nose drops or a nasal spray, travels through the main nerve in the face and collects in high concentrations in the teeth, jaw, and other structures in the mouth. The discovery could lead to a new generation of drugs for ‘needle-less’ treatment of dental pain, migraine, and other painful conditions of the human face.

The researchers note that drugs administered in the nose travel along nerves and go directly to the brain. One of those nerves is the trigeminal nerve, which controls the face, nose and mouth. Until now, however, scientists never checked to see whether intranasal drugs passing along that nerve might reach the teeth, gums and other areas of the face and mouth and aid in reducing pain.

They found that lidocaine or Xylocaine, sprayed into the noses of laboratory rats, quickly traveled down the trigeminal nerve and collected in their teeth, jaws, and mouths at levels 20 times higher than in the blood or brain. This approach could provide a more effective and targeted method for treating dental pain/anxiety, trigeminal neuralgia (severe facial pain), migraine, and other conditions, the scientists say.

Furthermore, the scientists discovered an improved future location to administer anesthetic, the maxillary sinus. The maxillary sinus is a golfball-sized space located underneath each cheek where drugs can be sprayed. Delivery into this confined space may provide an even more rapid and focused delivery of anesthetic.

The needle used by dentists to block pain could be replaced by the simple sniff of a local anesthetic thanks to a new discovery. (Credit: iStockphoto)

I know first-hand about fear of the dentist because my boyfriend Mariano had that problem. He also had a less common problem; he had a nasty scar from a ruptured appendix. So what could possibly be good news about a ruptured appendix? Well, researchers have discovered some interesting things about that useless remnant that only causes problems and they’ve discovered that it isn’t so useless after all!

IT GETS NO RESPECT

The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when researchers at Duke University Medical Center discovered that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria hang out until they’re needed to repopulate the gut after a nasty case of diarrhea, for example.

Now, some of those same researchers are back, with a report of the first-ever study of the appendix through the ages. Writing in the Journal of Evolutionary Biology, Duke scientists and collaborators from the University of Arizona and Arizona State University conclude that Charles Darwin was wrong: The appendix is a whole lot more than an evolutionary remnant. Not only does it appear in nature much more frequently than previously acknowledged, but it has been around much longer than anyone had suspected.

"Maybe it’s time to correct the textbooks," says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. "Many biology texts today still refer to the appendix as a ‘vestigial organ.’"

Parker and his colleagues found that the appendix has evolved at least twice, once among Australian marsupials and another time among rats, lemmings and other rodents, selected primates and humans. They theorize that the appendix has been around for at least 80 million years, much longer than we would estimate if Darwin’s ideas about the appendix were correct. Darwin said that the appendix in humans and other primates was the evolutionary remains of a larger structure, called a cecum, which was used by now-extinct ancestors for digesting food.

The latest study demonstrates two major problems with that idea. First, several living species, including certain lemurs, several rodents and a type of flying squirrel, have a large cecum which helps them digest their food. But it also has an appendix attached to it. Second, the appendix is actually quite widespread in nature. The scientists have found that more than 70 percent of all primate and rodent families contain species with an appendix. Darwin had thought the appendix appeared in only a small handful of animals.

But Darwin didn’t have access to information on all the animals that have been discovered in the last hundred years or so. If he had known that there were species with an appendix attached to a large cecum, and if he had known how common they were he probably wouldn’t have thought the appendix was a “vestige of evolution."

He also didn’t know that appendicitis, or inflammation of the appendix, is not caused by a faulty appendix, but because of industrialized society and improved sanitation. Our immune systems don’t have much to do anymore and more and more often, as is the case in appendicitis, the immune system is turning on us instead of invading germs.

That notion wasn’t proposed until the early 1900’s, and medicine didn’t get a really good grip on the concept until the mid 1980’s. Darwin had no way of knowing that the function of the appendix could be rendered obsolete by cultural changes that included widespread use of sewer systems and clean drinking water.

Dr. Parker says that since we now understand the normal function of the appendix, a critical question to ask is whether we can do anything to prevent appendicitis. He thinks the answer may lie in devising ways to challenge our immune systems today in much the same manner that they were challenged back in the Stone Age. "If modern medicine could figure out a way to do that, we would see far fewer cases of allergies, autoimmune disease, and appendicitis."

Normal location of the appendix relative to other organs of the digestive system (frontal view). (Credit: Wikimedia Commons)

So, I think you’ll agree that a less painful trip to the dentist is really good news and figuring out how to avoid appendicitis is also good for us. But as a general rule, bad teeth and appendicitis aren’t likely to kill you, so our next good news story may be a little more important. Doctors are slowly but surely zeroing in on a silent killer.

STALKING A KILLER

Ovarian cancer kills nearly 15,000 women in the United States each year, and fewer than half of the women diagnosed with the disease survive five years. The major reason is that ovarian cancer doesn’t have many overt symptoms. It doesn’t cause pain until the very late stages, there’s no suspicious discharge or color changes, no coughing, no swelling. By the time symptoms develop, it too late. A screening test that detects ovarian cancer early, when it is still treatable, would definitely reduce the high mortality rate, but scientists didn’t know where the tumors originated or what they looked like in the early stages.

Now, researchers at the Fox Chase Cancer Center in Philadelphia think they may have answered both questions. Their study states that they’ve found early tumors and precancerous lesions called inclusion cysts that fold into the ovary from its surface.

"This is the first study giving very strong evidence that a substantial number of ovarian cancers arise in inclusion cysts and that there is indeed a precursor lesion that you can see, put your hands on, and give a name to," says Jeff Boyd, Ph.D., Chief Scientific Officer at Fox Chase and lead author on the study, which also involved colleagues at the Memorial Sloan-Kettering Cancer Center. "Ovarian cancer most of the time seems to arise in simple inclusion cysts of the ovary, as opposed to the surface epithelium."

Clinicians and researchers have been looking for early ovarian tumors and the precancerous lesions from which they develop for years without success. In this study, Boyd and colleagues used a combination of traditional microscopy and molecular approaches to reveal the early cancers.

To learn how and where the tumors arise, the researchers examined ovaries removed from women with BRCA mutations, who have a 40% lifetime risk of developing ovarian cancer, and from women without known genetic risk factors. In both groups, they found that the cells in the inclusion cysts were dramatically different compared to the normal ovarian surface cells. The cells in the inclusion cysts had a much higher rate of control cell division and chromosome movement. And, of course, cancer is simply uncontrolled cell division.

They also used a technique that can be used to identify individual chromosomes in cells. When they did this, they saw that cells from very early tumors and precursor lesions frequently carried extra chromosomes. In fact, the team found that 9% of the normal cells isolated from the cysts had extra chromosomes, even though the tissue appeared completely benign under the microscope. By contrast, virtually none of the cells isolated from the surface of the ovary, which was previously thought to be the site of early ovarian cancers, carried extra chromosomes.

Using these new data on the origin of ovarian cancer, Boyd and others can now start to develop screening tests, perhaps based on molecular imaging that could be used to detect early ovarian cancers in asymptomatic women.