Poor oral health may increase the risk of pancreatic cancer among African American women

Boston University School of Medicine

(Boston)-- African American women with poor oral health may be more likely to get pancreatic cancer (PC).
In the U.S., studies show that African Americans are more likely to get pancreatic cancer than Caucasians. Poor oral health, specifically adult tooth loss and periodontal disease prevalence, has a similar pattern. Using data from the Black Women's Health Study, researchers from the Slone Epidemiology Center at Boston University found that compared to African American women who showed no signs of poor oral health, those who reported adult tooth loss had a substantially increased risk of PC. This association become even stronger for those who had lost at least five teeth.
According to the researchers, these observations may be related to oral bacteria and the inflammation caused by certain bacteria. In previous studies among different populations the presence of circulating antibodies to selected oral periodontal pathogens was associated with increased risk of PC.
"Oral health is a modifiable factor. Apart from avoiding cigarette smoking, there is little an individual can do to reduce risk of PC. Improving access to low cost, high quality dental care for all Americans may decrease racial disparities in this cancer," said Julie Palmer, ScD, associate director of BU's Slone Epidemiology Center and a professor of epidemiology at BUSPH.

New technique could help regrow tissue lost to periodontal disease

According to the U.S. Centers for Disease Control and Prevention, about half of all Americans will have periodontal disease at some point in their lives. Characterized by inflamed gums and bone loss around teeth, the condition can cause bad breath, toothache, tender gums and, in severe cases, tooth loss. Now, in ACS Nano, researchers report development of a membrane that helps periodontal tissue regenerate when implanted into the gums of rats.
To regrow lost gum tissue and bone, scientists have tried implanting pieces of polymers that form a protected niche near the root of a tooth, recruiting nearby stem cells and helping them differentiate into new gum and bone cells. However, a second surgery is usually required to remove the polymeric membrane, which can get in the way of the healing process. Although researchers have developed biodegradable membranes, these materials don't tend to work as well for re-growing periodontal tissue. Alireza Moshaverinia, Paul Weiss and colleagues wanted to develop a membrane that would enhance periodontal tissue regeneration and then be absorbed by the body when healing was complete.
The researchers made nanofibrous membranes of poly(ε-caprolactone), a biocompatible polymer already approved for medical applications. They then coated the membrane with polydopamine (PDA), a synthetic polymer that mimics the sticky protein that mussels use to attach to wet surfaces. In the lab, dental-derived stem cells adhered to the membrane and differentiated. The PDA coating also attracted calcium and phosphate ions, leading to early bone mineralization. When the researchers implanted the membranes into the gums of rats with periodontal defects, bone at the defect sites regenerated to normal levels within eight weeks. By this time, the membranes had degraded and were absorbed by the rats. Now, the researchers are working on adding other components to the membrane that aid healing and prevent infection.

Tissue-engineering approach to TMJ disorders S

Here's something to chew on: One in four people are impacted by defects of the temporomandibular - or jaw - joint. Despite the pervasiveness of this affliction, treatments are lacking, and many sufferers resort to palliative measures to cope with the pain and debilitation it causes.
"The TMJ is central to chewing, talking and so many other daily activities, so when this crucial joint is impaired, there are significant negative effects on quality of life," said Kyriacos A. Athanasiou, Distinguished Professor of biomedical engineering at the University of California, Irvine. "The problem may start with slight pain and clicking and get progressively worse to the point where it's not just impacting the jaw but the entire body."
Athanasiou is senior author on a paper published recently in the Cell Press journal Trends in Molecular Medicine that examines the causes of temporomandibular disorders, past failures in treating them, and new approaches based on tissue-engineering innovations developed in his laboratory. Co-authors are Ryan Donahue, UCI graduate student researcher in biomedical engineering, and Jerry Hu, UCI principal development engineer in biomedical engineering.
Temporomandibular disorders can be the result of sudden injuries or wear and tear over time. The cartilage disc between the mandible and the temporal bone is subject to thinning or perforation. The condition usually affects patients between the ages of 20 and 50. Most strikingly, premenopausal women are eight times more likely to experience jaw joint problems than men - which Athanasiou calls the TMJ gender paradox.
Typical treatments include physical therapy, splints and adjustments, corticosteroid injections and pain medications. Only about 5 percent of sufferers are candidates for surgical interventions. The TMJ is a joint like many others in the body, and surgeries to repair knees, elbows, hips and shoulders are commonplace, so why are operations on the jaw so rare?
"It has to do with the proximity of the TMJ to the brain," Athanasiou said. "Back in the 1980s, many patients - primarily women - came forward with issues they had with the TMJ. The solution at the time was to insert a spacer between the two bones articulated in the jaw."
The spacer was made of Teflon, a material approved by the U.S. Food and Drug Administration.
"It turns out that Teflon was an absolute catastrophe for all of those women," Athanasiou said. "Because of the large mechanical forces generated in the jaw, the Teflon broke up into pieces, and because of the proximity of the TMJ to the brain, those pieces somehow found their way into the brain."
This fiasco set back therapies for temporomandibular disorders for decades, but now Athanasiou and his colleagues in UCI's Department of Biomedical Engineering are working on new approaches that eschew synthetic materials entirely. They're developing biological TMJ discs in the laboratory that will be suitable for implantation in humans.
"The end product that we aspire to use for treating afflictions of TMJ discs is a tissue-engineered product that's fully alive, biological and mechanically comparable to the real thing," Donahue said. "So even if it breaks down, it will be like any other biological component, without having pieces of foreign material entering the brain."
In work detailed in a study published in Science Translational Medicine in June 2018, Athanasiou's team successfully took cells from the rib cartilage of a Yucatan miniature pig, grew them in their laboratory and implanted the tissue-engineered construct into a separate animal.
Whereas some researchers may place bioengineered cells in some other part of an animal's body - on the back of a mouse, for example - Athanasiou said a key aspect of his group's work is to put the new disc in the exact place as the old one so it will be subject to all the normal stresses of the joint.
"In eight weeks, we saw complete functionality of the TMJ disc, whereas the ones we left untreated deteriorated completely, developing full osteoarthritis in the joint," Hu said. "So we were able to show that by using our tissue-engineering approach in a large-animal model, we could achieve exceptional healing."
Athanasiou said his team's goal now is to conduct trials in more large-animal models to determine if their solution will ultimately work in humans. A major hurdle will be gaining regulatory approval from the FDA, but Athanasiou recently received some encouraging signals from the agency.
"The FDA has asked if we could help them figure out how to go about developing processes for bringing TMJ products to the market," he said. "We would be delighted to help create that pathway."

Periodontitis may raise the risk for developing dementia

Gum disease (gingivitis) that goes untreated can become periodontitis. When this happens, the infection that affected your gums causes loss in the bone that supports your teeth. Periodontitis is the main cause of tooth loss in adults.Interestingly, periodontitis is also a risk factor for developing dementia, one of the leading causes for disability in older adults. A United Nations forecast estimates that 1 in 85 individuals will be diagnosed with Alzheimer's disease, a form of dementia, by the year 2050. Reducing the risk factors that lead to dementia and Alzheimer's disease could potentially lower older adults' chances of developing those conditions.
Recently, researchers in South Korea studied the connection between chronic periodontitis and dementia. They published their findings in the Journal of the American Geriatrics Society.
The research team examined information from the National Health Insurance Service-Health Screening Cohort (NHIS-HEALS). In South Korea, the NHIS provides mandatory health insurance covering nearly all forms of health care for all Korean citizens. The agency also provides health screening examinations twice a year for all enrollees aged 40 years or older and maintains detailed health records for all enrollees.
The researchers looked at health information from 262,349 people aged 50 or older. All of the participants were grouped either as being healthy (meaning they had no chronic periodontitis) or as having been diagnosed with chronic periodontitis. The researchers followed the participants from January 1, 2005 until they were diagnosed with dementia, died, or until the end of December 2015, whichever came first.
The researchers learned that people with chronic periodontitis had a 6 percent higher risk for dementia than did people without periodontitis. This connection was true despite behaviors such as smoking, consuming alcohol, and remaining physically active. The researchers said that to their knowledge, this is the first study to demonstrate that chronic periodontitis could be linked to a higher risk for dementia even after taking lifestyle behaviors into account.
The researchers suggested that future studies be conducted to investigate whether preventing and treating chronic periodontitis could lead to a reduced risk of dementia.

How a common oral bacteria makes colon cancer more deadly

Researchers at the Columbia University College of Dental Medicine have determined how F. nucleatum -- a common oral bacteria often implicated in tooth decay -- accelerates the growth of colon cancer. The study was published online in the journal EMBO Reports.
Why it matters
The findings could make it easier to identify and treat more aggressive colon cancers. It also helps explain why some cases advance far more quickly than others, thanks to the same bacteria found in dental plaque.
Background
Colon cancer is the second leading cause of cancer death in the U.S. Researchers have long known that the disease is caused by genetic mutations that typically accumulate over the course of a decade. "Mutations are just part of the story," says study leader Yiping W. Han, PhD, professor of microbial sciences at Columbia University's College of Dental Medicine and Vagelos College of Physicians & Surgeons. "Other factors, including microbes, can also play a role."
Scientists have also demonstrated that about a third of colorectal cancers are associated with a common oral bacterium called F. nucleatum. Those cases are often the most aggressive, but nobody knew why. In a prior study, Han's research team discovered that the bacterium makes a molecule called FadA adhesin, triggering a signaling pathway in colon cells that has been implicated in several cancers. They also found that FadA adhesin only stimulates the growth of cancerous cells, not healthy cells. "We needed to find out why F. nucleatum only seemed to interact with the cancerous cells," says Han.
What the study found
In the current study, the researchers found in cell cultures that noncancerous colon cells lack a protein, called Annexin A1, which stimulates cancer growth. They then confirmed both in vitro and later in mice that disabling Annexin A1 prevented F. nucleatum from binding to the cancer cells, slowing their growth.
The researchers also discovered that F. nucleatum increases production of Annexin A1, attracting more of the bacteria. "We identified a positive feedback loop that worsens the cancer's progression," says. Han. "We propose a two-hit model, where genetic mutations are the first hit. F. nucleatum serves as the second hit, accelerating the cancer signaling pathway and speeding tumor growth."
Clinical implications
The researchers then looked at an RNA-sequencing dataset, available through the National Center for Biotechnology Information of 466 patients with primary colon cancer. Patients with increased Annexin A1 expression had a worse prognosis, regardless of the cancer grade and stage, age, or sex.
Next steps
The researchers are currently looking for ways to develop Annexin A1 as a biomarker for more aggressive cancers and as a potential target for developing new treatments for colon and other types of cancer.

Dental fillings could last twice as long

A compound used to make car bumpers strong and protect wood decks could prevent return visits to the dentist's office.
A team of researchers with the OHSU School of Dentistry in Portland, Oregon, have created a filling material that's two times more resistant to breakage than standard fillings, according to a study published by the journal Scientific Reports. The new filling uses the additive thiourethane, which is also in protective coatings for cars and decks.
The team also has developed an adhesive that's 30 percent stronger after six months in use than adhesives that are currently used to keep fillings in place. This new adhesive was described in a recent study published in the journal Dental Materials.
Combined, the new adhesive and the composite are designed to make longer-lasting dental restorations.
"Today's dental restorations typically only last seven to 10 years before they fail," said Carmem Pfeifer, D.D.S., Ph.D., corresponding author of the studies published in Scientific Reports and Dental Materials. Pfeifer is an associate professor of restorative dentistry (biomaterials and biomechanics) in the OHSU School of Dentistry.
"They crack under the pressure of chewing, or have gaps form between the filling and the tooth, which allow bacteria to seep in and a new cavity to form," Pfeifer said. "Every time this happens, the tooth under the restorations becomes weaker and weaker, and what starts as a small cavity may end up with root canal damage, a lost tooth or even life-threatening infections.
"Stronger dental materials mean patients won't have to get fillings repaired or replaced nearly as often," she said. "This not only saves them money and hassle, but also prevents more serious problems and more extensive treatment."
The adhesive described in the Dental Materials study uses a specific kind of polymer - known as (meth)acrylamides - that is much more resistant to damage in water, bacteria and enzymes in the mouth than standard adhesives currently used in dentistry. The composite material described in Scientific Reports uses thiourethane, which holds up much better to chewing.