OH Digest: Hope for heart disease patients, saving near-extinct rhinos, and more

OH Digest: Hope for heart disease patients, saving near-extinct rhinos, and more

Researchers have figured out how to turn off certain genes in the liver that can cause dangerous health problems. (Photo credit: istock/vchal)

By Jacob Williamson-Rea

Our weekly round-up compiles stories and news, both from here at Penn and around the world, that highlight the intersection of animal, environmental, and human health.

Hope for heart disease patients
Science, July 9, 2018
Using a non-human primate animal model, researchers were able to edit and turn off genes in the liver, which has the potential to lower blood cholesterol levels, treat heart disease, and tackle some genetic diseases.

Scientists hope test-tube embryos can save near-extinct white rhino
Reuters, July 4, 2018
There are only two northern white rhinoceroses left, and both are female. Luckily, scientists collected semen from bull rhinos before they died, and in an attempt to save the near-extinct species, will attempt to create hybrid embryos.

Nerve cells that help control hunger have been IDed in mice
Science News, July 5, 2018
Mice and humans contain similar neurons that control appetite, a new study finds. These neurons might play a role in attacking obesity and eating disorders.

A fence built to keep out wild dogs has dramatically altered the Australian landscape
Science, July 6, 2018
Researchers discovered that a century-old fence completely changed part of the Australian desert. The fence was built to keep dingoes away from livestock but has now entirely modified the area’s ecosystem, including predator-prey relationships and vegetation.

Is sunscreen killing coral reefs?
CNN, July 9, 2018
Hawaii recently banned sunscreens that contain oxybenzone and octinoxate. These chemicals impact coral health, but do they affect animals and humans as well?

Orcas of the Pacific Northwest are starving and disappearing
The New York Times, July 9, 2018
King salmon are dying off, which means Pacific Northwest orcas have nothing to eat. Orcas have been endangered since 2005, and scientists worry that with this latest setback, the mammals won’t make a comeback.

The ice cream conundrum

The ice cream conundrum

Penn researchers explain what happens when ice cream and other frozen treats cause “brain freeze” and tooth sensitivity.

By Jacob Williamson-Rea

As summer temperatures skyrocket, people reach for ice-cold drinks and ice cream, some 23 pounds per American per year, according to the International Dairy Foods Association. Along with short-term refreshment, these chilly delights can also cause sharp, shooting mouth pain or the occasional “brain freeze” although the two reactions are completely unrelated, says neurologist Roderick Spears of Penn Medicine.

“Brain freeze starts with a cold stimulus, such as ice cream, touching the palate, the roof of the mouth,” says Spears, a clinician in the Department of Neurology in the Perelman School of Medicine. The cold temperature causes vasoconstriction, when blood vessels constrict or shrink quickly.

But this isn’t what causes brain freeze. Instead, the pain comes from a rapid warming process called vasodilation, during which the vessels rebound back to regular size to counteract the initial rapid cooling. This signal heads to the brain via the trigeminal nerve. Because the trigeminal nerve is responsible for facial sensation, people often perceive this ice cream–related discomfort in the forehead or face.

“This pain can last for anywhere from a few seconds to a few minutes,” says Spears. “But there’s an easy way to avoid it.” Slow down. A study published in The BMJ (formerly the British Medical Journal) discovered that brain freeze occurs more frequently when people consume ice cream quickly.

Such a solution can’t help someone whose teeth hurt from sensitivity to the cold, explains Panagiota Stathopoulou, a periodontist with Penn Dental Medicine. People with healthy teeth and gums shouldn’t experience tooth sensitivity, she says. If this is happening, it could indicate that something is wrong.

“When someone experiences tooth pain or sensitivity, pain stimuli comes in contact with the tooth either directly or indirectly,” says Stathopoulou, an assistant professor of periodontics and director of the Postdoctoral Periodontics Program.

The tissue inside the root canal of the tooth, called the pulp, contains nerves that are responsible for the sharp, uncomfortable feelings some people occasionally experience when they consume cold food and drinks.

Consistent and painful tooth sensitivity can result from several problems. Each tooth has several layers. The exterior layer is a hard white covering called enamel. Just beneath the enamel, a softer, bony tissue called dentin makes up the bulk of the tooth. And dentin wraps around the pulp cavity, which contains living tissue and nerves.

The enamel serves as the pulp’s first layer of defense, with dentin as backup. But dentin is porous and contains tunnels called tubules, which enable the pulp to communicate with the tooth’s exterior. Normally, such communication is crucial, but when enamel breaks down those tubules allow all external oral stimuli, including ice cream, cold beer, even air, to travel directly through the porous dentin and into the pulp.

“This is not fun,” says Stathopoulou. “Additionally, the root of the tooth is normally protected by our gums. But if our gums recede, then we’ve lost that defense as well. Gum recession is often caused by overzealous brushing, and if it’s minor this problem can be solved easily by using a softer brush, better technique, and desensitizing toothpaste.”

Desensitizing toothpastes contain high levels of fluoride, potassium, and other ingredients and often resolve minor sensitivity problems, but some issues require more complicated treatments. Stathopoulou says that someone who experiences acute tooth pain or persistent tooth sensitivity should see a dentist to rule out more serious causes like a cavity or cracked tooth.

OH Digest: Medical students learn at the zoo, researchers decode the koala genome, and more.

OH Digest: Medical students learn at the zoo, researchers decode the koala genome, and more.

Harvard Medical Students learn to treat species like the red panda above through a collaboration between Harvard Medical School and Zoo New England. (Photo credit: Flickr Creative Commons/Mathias Appel)

By Jacob Williamson-Rea

Our weekly round-up compiles stories and news, both from here at Penn and around the world, that highlight the intersection of animal, environmental, and human health.

Doctor, your patient is waiting. It’s a red panda.
The New York Times, June 29, 2018
During a clinical elective at the Franklin Park Zoo in Boston, Harvard Medical School students treat animal patients instead of humans. The rotation reinforces the future doctors’ understanding of our ecosystems’ interconnectedness through translational and veterinary medicine.

Biodiversity is the ‘infrastructure that supports all life’
The Guardian, June 28, 2018
E. O. Wilson developed the concept of “Half Earth,” which suggests we must set aside 50 percent of this planet as nature preserves to sustain life as we know it. Scientists are considering this idea’s potential ahead of the 2020 UN Biodiversity Convention in Beijing.

These animals depend on darkness. But humans have ruined their nights.
The Washington Post, June 29, 2018
City development, noise pollution, and light pollution have influenced nocturnal wildlife for years. But the widespread switch from sodium lamps—which give off orange light—to the white and blue LEDs in 2009 might have negative consequences, according to a recent study.

Saving koalas: Gene study promises solution to deadly sex disease
BBC, July 2, 2018
Though koalas can stomach the often-poisonous eucalyptus plant, numerous STDs, including a recent bout of chlamydia, have plagued the marsupial population. Scientists say they can develop an effective vaccine against this disease by decoding the koala genome.

Alarming polio outbreak spreads in Congo, threatening global eradication efforts
Science, July 2, 2018
The recent Ebola outbreak in Congo dominated news headlines. But another ailment has been quietly, rapidly spreading there, too. Polio has already paralyzed 29 children and made its way to the border of Uganda, far beyond the original “outbreak zone.”

Horses had dentists 3,000 years ago
National Geographic, July 2, 2018
It appears that horse riding and horse dentistry emerged simultaneously more than 3,000 years ago. A study published in Proceedings of the National Academy of Sciences discovered archaeological evidence that humans sawed and pulled infected horse teeth, which likely allowed the animals to remain healthy, enabling longer travel.


Why are dogs afraid of fireworks?

Why are dogs afraid of fireworks?

Carlo Siracusa, director of Animal Behavior Service at Ryan Hospital, part of the University of Pennsylvania’s School of Veterinary Medicine, offers some tips on how to make your pets feel safe during thunderstorms and fireworks. Click here for additional suggestions and some more in-depth information.

Why are dogs afraid of thunderstorms and fireworks?
Many dogs are afraid of loud, sudden, unpredictable noises, not just thunderstorms and fireworks. Occasionally, storms cause real damage to the dog’s environment: Trees fall on houses, lightning strikes, power goes out, or flooding occurs. Fireworks have many of the features of thunderstorms, including various explosions and other strange noises, plus flashes of light. Whether because of years of frightening experiences or decreased tolerance, these fears often appear for the first time in adult or senior dogs.

What are the signs of this kind of fear?
For a thunderstorm, the behavioral signs often begin before a storm arrives. Generally speaking, such signs include panting; pacing; whining; salivating; trembling; urination and defecation (including diarrhea) in the house; digging and clawing at floors and walls; chewing household objects, woodwork or walls; attempts to hide or escape (which may include digging and chewing); running away if escape occurs; and attempts to stay near a family member.

Some dogs exhibit redirected aggression to other household dogs because of their fear. This can result in dog fights with injury, as the fearful dog attacks another dog in the home. There is also a danger in multi-dog households that another dog will attack the dog behaving fearfully. This is not an attempt to “correct” the behavior; it is an emotional response to the behaviorally agitated state of the fearful dog.

What are some behavioral management options?
Because fear is not an operantly conditioned behavior, it can neither be effectively punished or rewarded. The goal of managing this fear behaviorally is to change the dog’s emotional state from frightened and distressed to neutral or even content. Though limited, there are a few options. First, do not ignore your dog during storms or fireworks. Ignoring a fearful, panicky dog deprives him of whatever comfort and psychological support you can provide. It also leaves him without any information about what he should be doing instead. Also, never punish a dog acting fearfully. Punishment only inhibits behavior; it does not calm. For puppies and young dogs, it may be helpful to try to do pleasant things with them during storms or fireworks, in an effort to prevent fear from developing.

Some dogs are able to direct their anxiety to destroying “sacrifice items” such as cardboard boxes or paper items like old phone books. This destructive behavior can function as a way to displace the dog’s anxiety onto a pleasurable activity. If there is an activity your dog can’t get enough of, do this during storms and fireworks. This can include fetch, chase games, even cuddling and petting, or holding the dog firmly next to you. If the fear-inducing activities are occurring at night, some dogs can be comforted by being allowed in bed with you.

What are some environmental management options?
Some dogs respond well to having a “safe haven” where they can hide and be reasonably secure and comfortable. This can be a room, a large closet, even a basement. Some dogs prefer a bathroom, especially the bathtub or shower. During storms and fireworks, keep dogs who are aggressive or targets of aggression separate from other household dogs. This can make it more complicated to find an appropriate safe haven for the fearful dog. Some dogs cannot overcome their fear with just environmental changes and therefore, it might be appropriate to discuss medication options with a veterinarian.

Carlo Siracusa is a clinical assistant professor of behavior medicine at the University of Pennsylvania School of Veterinary Medicine.