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Biomedical Engineering

The Biomedical Engineering blog is the place for conversation and discussion about topics related to engineering principles of the medical field. Here, you'll find everything from discussions about emerging medical technologies to advances in medical research. The blog's owner, Chelsey H, is a graduate of Rensselaer Polytechnic Institute (RPI) with a degree in Biomedical Engineering.

Regenerating Teeth

Posted October 14, 2014 12:00 AM by Chelsey H

No more veneers? Maybe. This blog post is timely considering my sister fell last week while running and chipped her front tooth in half. I wish I had known to suggest that she seek laser treatment to encourage regrowth of her broken tooth (although I doubt she would have wanted to wait so long).

Research shows that lasers can help regenerate heart, skin, and nerve tissues. Low levels of laser light can trigger chemical reactions that promote wound healing, reduce inflammation, and treat pain. New research in Science Translational Medicine shows that lasers can help regrow parts of broken teeth and potentially make fillings, crowns, and other dental necessities obsolete.

A false-color image from a scanning electron microscope depicting the scaffold seeded with cells used to assess laser treatment effects.

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For the study, scientists at Harvard University looked at dentin, the tissue that makes up the bulk of human teeth. Dentin is harder than bone but softer than the enamel that coats teeth. The goal of the research was to encourage dental stem cells to regenerate as dentin. But instead of implanting modified dental stem cells or injecting chemicals to control dental stems cells in patients, the researchers wanted to activate proteins, known as growth factors, that are already in the body and use them to manipulate dental stem cells through the use of lasers.

Instead of using synthetic materials, such as ceramics, to repair a tooth, a laser would be shone on the tooth and soft pulp underneath (from damage). The laser generates chemicals known as reactive oxygen species which activate a growth factor called transforming growth factor beta-1 (TGF-b1) in the body. This molecule stimulates dental stem cells to repair teeth as well as many other tissues.

Experiments have been done on rats and adult dental stem cells extracted from human teeth. Results show that low levels of laser light activated TGF-b1 and led to the generation of dentin-forming cells. The next step is taking their work to human clinical trials.

7 comments; last comment on 10/17/2014
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Flu Season - What You Think You Know

Posted October 11, 2014 12:00 AM by Chelsey H
Pathfinder Tags: flu flu shot Myth vaccine

'Tis the season for flu shots. Most employers and pharmacies offer free flu shots on a walk-in bases. But should you get one? Are you scared it might give you the flu? Here are a few flu shot myths debunked.

1. The flu shot will give you flu

According to the CDC this isn't the case. The virus is killed during the production of the vaccine and therefore cannot cause infection. Batches are tested randomly, with a group of people getting the vaccine and another group getting a shot of salt water. The only noticeable difference in symptoms was increased soreness in the arm and redness at the injection site. The tenderness at the injection site is caused by the immune system making antibodies to the killed viruses and usually dissipates within two days.

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Also, the vaccine doesn't kick in for two weeks, so those who claim the shot gave them the flu might have gotten it the old fashion way and their body wasn't right to fight it off yet.

2. It's better to wait so the efficacy doesn't wear off

The shots are designed to last the entire flu season, except for some children who may need two doses. This is also a bad idea since the vaccine takes two weeks to kick in leaving you exposed for even longer.

3. The flu shot is dangerous during pregnancy

Also not true. It is considered an essential part of prenatal care. Pregnant women are considered a risk group for flu complications such as pneumonia, infections, and dehydration. Babies cannot be vaccinated until they have reached six months of age, but the antibodies they received in utero may help protect them.

4. The flu isn't so bad - bring it on

The seasonal flu changes every season and causes more damage some years over others. And you change every year, making the flu more damaging one year over another. Just get the shot.

5. It doesn't work

This is only partly true. The vaccine doesn't work all the time, but it does confer some level of protection. According to the CDC, for the 2010-11 season the flu shot was about 60% effective for all age groups combined. And some years it's even higher.

I'm getting the flu shot this weekend. Are you?

Read more about flu shot myths here and here.

36 comments; last comment on 10/18/2014
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3D Breast Cancer Detection

Posted September 23, 2014 12:00 AM by Chelsey H

Exciting news for GE this month! The FDA has approved General Electric's three-dimensional tomosynthesis breast cancer screening technology. The approval means big opportunities for GE Digital X-Ray plant which makes 3D images for the company's new digital mammography imaging machine called SenoClaire. The plant is located in the Rensselaer Technology Park in North Greenbush, NY, employs 135 people and is designed to produce several thousand units annually.

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The new device is more effective than two-dimensional breast cancer screenings because it helps clinicians uncover small cancers. The new technology was tested at several medical centers, including Massachusetts General Hospital. The technology employs a low-dose short X-ray sweep around the positioned breast with nine exposures acquired using a "step-and-shoot" method, removing the potential motion from the tube and helping to reduce blur and increase image sharpness. "As a radiologist, it's important to offer technology like this for patients that produces higher image quality without increasing dose," said Dr. Murray Rebner MD, FACR, Professor of Diagnostic Radiology and Molecular Imaging at Oakland University William Beaumont School Of Medicine and Director of the Division of Breast Imaging and Intervention at Beaumont Hospital, Royal Oak.

SenoClaire is part of a breast cancer continuum which offers physicians and patients a complete suite of solutions from screening and diagnosis through treatment and monitoring. This machine, along with other solutions like contrast enhanced spectral mammography, automated whole breast ultrasound, and molecular breast imaging will equip healthcare providers with a comprehensive set of tools that will help their patients.

According to Tom Fiest, the general manager of North Greenbush Operation, the new technology is compatible with many stenograph machines already in use and presents an opportunity for hospitals and imaging centers to upgrade their cancer detection technology.

7 comments; last comment on 09/25/2014
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Toothpaste Debunked

Posted August 30, 2014 12:00 AM by Chelsey H

Most of us can go through our morning routines without thinking. (I guess that's the point of having a routine). But as you brush away your morning breath, have you ever stopped to think about what toothpaste actually is or why we use it?

Toothpaste has a technical term - dentifrice. And modern toothpaste ingredients sound like they should be boiling in a beaker somewhere, but it shows the long way that humans have come in dental hygiene. The first toothpastes were also used to clean the teeth and gums while freshening breath and preventing decay. The ingredients consisted of powdered ashes of ox's hoof with carbonized eggshells and pumice (ew!). Combined, it created a potent abrasive capable of scrubbing teeth without the need for a toothbrush. Many counties added their own "special ingredient" too. Greeks and Romans added crushed bone and seashells, and the Chinese added ginseng, herbs, and salt.

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The tooth powder wasn't developed until the 19th century by a British inventor. It started out of homemade poultices contrived out of chalk, charcoal, brink, dust, salt, burnt bread, and cinnamon (just for good measure). Many of the early mixtures ended up being too abrasive and taking out bits of enamel in addition to plaque, but they stayed popular until WWI.

By the turn of the 20th Century, a paste-like mixture became available made with hydrogen peroxide and baking soda. Dr. Washington Sheffield invented the collapsible toothpaste tube (made out of lead) and tubed toothpaste quickly usurped tooth powders. Crest was the first American toothpaste to include fluoride after more than a decade of privately-funded research. The ADA endorses the use of fluoride saying, "Crest has been shown to be an effective anti-cavity (decay preventative) dentifrice that can be of significant value when used in a conscientiously applied program of oral hygiene and regular professional care."

While the toothpaste tube may have a laundry list of strange ingredients, all toothpastes have a common set of active ingredient classes - abrasives, fluorides, and surfactants.

· Abrasives can make up as much as half of a tube of toothpaste and they serve to scrub the enamel of plaque. This minimizes the formation of cavities and other forms of tooth decay. Aluminum hydroxide, calcium carbonate, calcium phosphate, silicas-even household baking soda-can be employed for this role.

· Fluorides act to strengthen tooth enamel and counter the formation of cavities and gingivitis. Sodium fluoride is the most commonly used and it makes up about 1000 ppm a tube.

· Surfactants are a class of detergents employed as foaming agents. The foam makes sure the toothpaste gets all over the sink and mirror - OK, it actually makes sure the other two components are evenly distributed across the entire tooth.

The rest of the stuff includes stabilizers to keep the toothpaste from drying out, antibacterial agents to kill germs that cause gingivitis, and flavorants for the minty-freshness.

Toothpaste isn't going to be going anywhere anytime soon since a 2013 study by the University of Leeds found that people with white, evenly-spaced teeth are consistently viewed as more attractive than their snaggle-toothed peers. So brush up! It will keep you healthy and may help you get a date.

Adapted from What the Heck Is Toothpaste Anyway?

32 comments; last comment on 09/04/2014
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Don't Rush to Natural Sweetners

Posted August 23, 2014 12:00 AM by Chelsey H

"I'll have the pink one." That's what my mom always says when she is making her coffee. Of course she is referring to Sweet 'N Low, one of several brands of artificial sweeteners. I have never liked the weird tangy after-taste of artificial sweeteners, which has led to me using Stevia or agave in my coffee.

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These new low-cal sweeteners are derived from natural substances but their newness on the market means they haven't been well-studied for safety. According to Barry Popkin, a professor of nutrition at the school of public health at the University of North Carolina at Chapel Hill, even though the base comes from a nature, some sweeteners may have undergone chemical processing to extract them from their original sources. This process may affect their healthfulness.

Few details about the extraction process are provided by manufacturers, but the FDA has reviewed data and considers most of them to be generally safe. And the Center for Science in Public Interest (CSPI) believes the natural sweeteners are safer than aspartame and saccharin (the chemicals found in artificial sweeteners). The exception is Nectresse, a monk fruit extract. CSPI says it has been poorly tested for safety but since it's derived from a fruit, it is probably safe.

Don't get too excited about them being low calorie. There has been very little research done about how these sweeteners affect weight loss.

"Our research shows that artificial sweeteners do appear to reduce the risk for weight gain when combined with a healthy, well-balanced diet," Popkin says. The risk for weight gain and diabetes with artificial sweeteners is because they may interfere with the physiological responses that help regulate body weight and control sugar.

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When we taste something sweet, our bodies expect actual calories to hit our stomachs and we release insulin to prepare. But in the absence of actual calories, the insulin and other hormones cause your blood sugar to plunge and make you crave more sweets (i.e. overeat).

Experts think natural low-calorie sweeteners will have the same effect since the sweetness will jump-start the chain reaction. They may not be the best tool for weight management.

There is one tip - the overeating effect can be countered if you consume food that contains fiber. The fiber keeps insulin levels steady so blood sugar doesn't plunge.

35 comments; last comment on 09/26/2014
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Why Do People Get Goosebumps?

Posted July 27, 2014 3:44 PM by Chelsey H

Goosebumps, goosepimples, goose flesh…there are many words for the little bumps that form on your skin and many reasons why they form. Medically, they are called cutis anserine and they are a physiological phenomenon that has evolutionary significance. It was useful to our ancestors, but it's not much help to us.

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Speaking of ancestors, no one is 100% sure why they are called goosebumps. Many assume it's because when plucked, a goose leaves a bumpy flesh behind, but so do most birds. Additionally, numerous languages use the bird to describe the bumps; it's a mystery as to why goose is used in German, Italian, Russian, Polish and many other languages.

Goosebumps are caused by a contraction of miniature muscles called arrector pili muscles that are attached to each hair. The reflex of producing goose bumps is known as arasing, piloerection, or the pilomotor reflex. The contraction creates a shallow depression on the skin surface, causing the surrounding area to protrude (bump). The same contraction also causes the hair to stand up whenever the body feels cold. This adaption is useful for animals with thick hair. The rising hair expands the layer of air that serves as insulation to retain more heat. During the formation of goosebumps, the body is warmed from the muscle's tension in piloprection. In people this reaction is useless because we (well most of us) don't have a hair coat.

Goosebumps also signify an emotional response. For animals, the expanded hair makes them appear bigger when threatened in an attempt to scare off the threatening animal. People get goosebumps during emotional situations such as watching horror movies, listening to a song that brings back memories, or events such as winning in sports. This reaction is caused by a release of the stress hormone adrenaline. Adrenaline causes the contraction of skin muscles as well as tears, sweaty palms, racing heart, and trembling hands. Check out the video for more info.

In more recent news, a goosebump detector is being developed that could track such hair-raising moments in life. This could be used to detect a person's reaction to a new movie or online advertisement. It's made using a conductive polymer and a type of flexible silicon that is also biocompatible to create a postage stamp-sized sensor that could help monitor the physical and emotional states of consumers in real time. Not the noblest use of goosebumps, but it has potential.

So when a beautiful piece of music gives you chills or makes your hair stand on end, know that it's just your body's way of saying that something awesome is happening.

9 comments; last comment on 07/31/2014
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