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Research Shows Nicotine Residue Can Be Extracted From Dental Plaque On Ancient Tobacco Users Teeth

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A team of scientists including researchers from Washington State University has shown for the first time that nicotine residue can be extracted from plaque, also known as “dental calculus”, on the teeth of ancient tobacco users.

Their research provides a new method for determining who was consuming tobacco in the ancient world and could help trace the use of tobacco and other intoxicating plants further back into prehistory.

“The ability to identify nicotine and other plant-based drugs in ancient dental plaque could help us answer longstanding questions about the consumption of intoxicants by ancient humans,” said Shannon Tushingham, a WSU assistant professor of anthropology and co-author of a new study on the research in the Journal of Archaeological Science Reports.

“For example, it could help us determine whether all members of society used tobacco, or only adults, or only males or females.”

A new source of information

Tracing the ancient spread of tobacco in the Americas has traditionally relied on the presence of pipes, charred tobacco seeds and the analysis of hair and fecal matter. However, these items are rare in the archaeological record and are hard to link to particular individuals. As a result, tobacco use has been difficult to document archaeologically.

On the other hand, dental plaque adheres to the surfaces of teeth and mineralizes over time, preserving a wide range of substances that are in the mouth. It is easy to link to particular individuals because it can be removed directly from teeth.

Nevertheless, dental plaque was largely ignored by archaeologists until recently.

However, using modern and highly sensitive instrumentation, scientists have found they can detect and characterize trace amounts of a wide variety of compounds, including proteins, bacterial DNA, starch grains and other plant fibers in dental plaque.

Because nicotine is detectable in the dental plaque of contemporary smokers Tushingham and her collaborators wanted to find out if it also preserved in plaque taken from people who lived long ago.

She and David Gang, a professor in the WSU Institute of Biological Chemistry, Korey Brownstein, a graduate student in the WSU Molecular Plant Sciences Program, and Jelmer Eerkens, an anthropologist at the University of California, Davis, collaborated with members from the Ohlone tribe in San Francisco Bay to extract plaque from the teeth of eight individuals, buried between 6,000 and 300 years ago, and analyze it for nicotine.

Using ordinary dental picks, Eerkens and his team at UC Davis extracted the dental plaque from the ancient teeth and then sent it to Tushingham and Gang’s labs at WSU for analysis. The WSU researchers used liquid chromatography-mass spectrometry to test the samples for nicotine and other plant-based drugs like caffeine and atropine, a muscle-relaxant.

Among the samples they analyzed, two tested positive for nicotine, demonstrating for the first time that the drug can survive in detectable amounts in ancient plaque. One of these individuals, an adult man, was also buried with a pipe. A surprise came from the molar of an older woman, which also tested positive for nicotine.

“While we can’t make any broad conclusions with this single case, her age, sex, and use of tobacco is intriguing,” Eerkens said.

“She was probably past child-bearing age, and likely a grandmother. This supports recent research suggesting that younger adult women in traditional societies avoid plant toxins like nicotine to protect infants from harmful biochemicals, but that older women can consume these intoxicants as needed or desired.”

While the researchers did not detect evidence of any other plant-based drugs in this particular study, they believe dental plaque could be used help trace the use and spread of other intoxicants as well.

“We think a wide variety of plant-based, intoxicating chemicals could be detected in ancient dental plaque,” Brownstein said. “It really opens up a lot of interesting avenues of discovery.”

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Ibuprofen, Acetaminophen More Effective Than Opioids In Treating Dental Pain

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Opioids are not among the most effective — or longest lasting — options available for relief from acute dental pain, a new examination of the results from more than 460 published studies has found.

Ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs) alone or in combination with acetaminophen are better at easing dental pain, according to new research conducted with the School of Dental Medicine at Case Western Reserve University.

The study examining relief of acute pain in dentistry — recently featured on the cover of The Journal of the American Dental Association — evaluated the safety and efficacy of dozens of pain-relief options.

“What we know is that prescribing narcotics should be a last resort,” said Anita Aminoshariae, an associate professor in the dental school’s Department of Endodontics and one of the study’s authors.

Each day, more than 115 Americans die as a result of an opioid overdose, according to the National Institutes of Health.

“No patient should go home in pain,” Aminoshariae said.

“That means that opioids are sometimes the best option, but certainly should not be the first option.”

Aminoshariae said the goal of the systematic review was to summarize data — using five in- depth studies — of the effectiveness of oral-pain medications.

“The best available data suggests that the use of nonsteroidal medications, with or without acetaminophen, offers the most favorable balance between benefits and harms, optimizing efficacy while minimizing acute adverse events,” she said.

She cited the national opioid epidemic as one of many reasons why health-care providers should take note of the findings.

The research found that, for adults, a combination of 400 milligrams of ibuprofen and 1,000 milligrams of acetaminophen was superior to any opioid-containing medications studied.

“Our aim was to create a compendium detailing both the benefits and harms of these medications as a resource for dentists to use in their clinical decision-making,” Aminoshariae added.

The study also found that opioids or drug combinations that included opioids accounted for the most adverse side effects — including drowsiness, respiratory depression, nausea/vomiting and constipation — in both children and adults.

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Gum Disease May Be A Key Initiator Of Rheumatoid Arthritis Related Autoimmunity

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The results of a study presented at the Annual European Congress of Rheumatology (EULAR 2018) demonstrates increased levels of gum disease, and disease-causing bacteria, in individuals at risk of rheumatoid arthritis (RA).

“It has been shown that RA-associated antibodies, such as anti-citrullinated protein antibodies, are present well before any evidence of joint disease. This suggests they originate from a site outside of the joints,” said Dr Kulveer Mankia of Leeds Institute of Rheumatic and Muscoskeletal Medicine and the Leeds Biomedical Research Centre (study author).

“Our study is the first to describe clinical periodontal disease and the relative abundance of periodontal bacteria in these at-risk individuals. Our results support the hypothesis that local inflammation at mucosal surfaces, such as the gums in this case, may provide the primary trigger for the systemic autoimmunity seen in RA.”

Rheumatoid arthritis is a chronic inflammatory disease that affects a person’s joints, causing pain and disability. It can also affect internal organs. Rheumatoid arthritis is more common in older people, but there is also a high prevalence in young adults, adolescents and even children, and it affects women more frequently than men.

The prevalence of gum disease is increased in patients with RA and could be a key initiator of RA-related autoimmunity. This is because autoimmunity in RA is characterised by an antibody response to citrullinated proteins and the oral bacterium Porphyromonas gingivalis (Pg) is the only human pathogen known to express an enzyme that can generate citrullinated proteins.

“We welcome these data in presenting concepts that may enhance clinical understanding of the key initiators of rheumatoid arthritis,” said Professor Robert Landewé, Chairperson of the Scientific Programme Committee, EULAR.

“This is an essential step towards the ultimate goal of disease prevention.”

In results from the study, dentists diagnosed clinical gum disease in significantly more at-risk individuals than in healthy controls (73% vs. 38%, p=0.02). In addition, the percentage of sites with clinical attachment level (CAL) ?2mm, pocket depth (PD) ?4mm, bleeding on probing (BOP), periodontal disease (PDD), and active periodontal disease (PDD+BOP), were all significantly greater in the at-risk individuals compared to controls (p<0.05). In non-smokers, PDD and active PDD were more prevalent in at-risk individuals compared to controls.

DNA was isolated from the subgingival plaque, next to the gums, of each participant and used to measure the levels of three types of bacteria, Pg, Aggregatibacter actinomycetemcomitans (Aa) and Filifactor Alocis. Results showed that there was increased abundance of both Pg and Aa in at-risk individuals. However, in at-risk individuals, only Pg was significantly increased at healthy dental sites and was associated with the overall extent of gum disease (p<0.001).

The study included 48 at-risk individuals (positive test for anti-citrullinated protein antibodies, musculoskeletal symptoms but no clinical synovitis), 26 patients with RA and 32 healthy controls. The three groups were balanced for age, gender and smoking. At-risk individuals underwent ultrasound assessment to assess for subclinical synovitis; only two (4%) were found to have ultrasound synovitis. Dentists examined six sites per tooth in each participant and a clinical consensus was agreed in each by three dentists.

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Cellular Messengers Communicate With Bacteria In The Mouth

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A new UCLA-led study provides clear evidence that cellular messengers in saliva may be able to regulate the growth of oral bacteria responsible for diseases, such as periodontitis and meningitis.

The study’s findings, which suggest that a body’s cellular messengers play an important role in managing the amount of good and bad bacteria in the mouth, are published online and will appear in the May issue of the Journal for Dental Research.

Study authors Dr. David Wong, professor of oral biology and associate dean for research at the UCLA School of Dentistry, and Dr. Wenyuan Shi, chief executive officer and chief science officer at the Forsyth Institute, an oral health research institute in Cambridge, Massachusetts, asked the question of whether our RNA — the cellular messengers — can communicate with harmful bacteria in the mouth.

RNA acts as a messenger that transports DNA’s instructions to other parts of the cell. Small regulatory noncoding RNAs, known as sRNAs, regulate our genes. A new class of sRNAs has also been discovered called tsRNA, which is transfer RNA-derived small RNA. tsRNA is found in human body fluids, including blood, tears and saliva.

The research team began by analyzing salivary sRNAs and found many of them belong to tsRNA with their sequences matching the partial transfer RNA sequences of several Gram-negative oral bacteria — bacteria that have a highly toxic outer layer that can cause periodontal disease. These salivary tsRNAs could potentially affect bacterial tRNA, a type of RNA molecule that helps decode a messenger RNA sequence into a protein and is required for bacterial growth. The Gram-negative bacterium used in the study to test this hypothesis was Fusobacterium nucleatum (F. nucleatum), the bacteria responsible for periodontitis.

The team showed that host cells respond to the presence of F. nucleatum by releasing specific tsRNA with sequence matching to tRNA of F. nucleatum. Furthermore, these released tsRNAs can inhibit the growth of F. nucleatum, but they have no effect on the growth of Gram-positive oral bacteria, such as Streptococcus mitis, a bacterium that responds to antibiotics.

“This study establishes that there is a clear channel of communication between RNA messengers and bacteria in our mouth,” said Wong, who holds the Felix and Mildred Yip Endowed Chair in Dentistry.

“Furthermore, we have shown that these messengers may play an important role in mediating interactions between bacteria and their host.”

Another significant study finding was the majority of tRNA bacteria sequences that show high sequence similarity with salivary tsRNAs came from antibiotic-resistant Gram-negative bacteria. This observation could lead to a better understanding of the mechanisms behind the growth of oral bacteria, resistance to antibiotics, and in-turn oral diseases, Wong said.

“Our findings could lead to new therapies to treat diseases caused by harmful bacteria,” said Shi, a former professor of oral biology at the UCLA School of Dentistry.

“As a convener for oral health and biotech experts, Forsyth is thrilled about collaborating with UCLA on this exciting research.”

For example, one of the hallmarks of periodontitis is a shift from mostly Gram-positive bacteria to mostly Gram-negative bacteria. With a better understanding of how Gram-negative bacteria grow, perhaps there is potential to reverse the growth or even kill Gram-negative bacteria.

“Our finding could potentially open a new door for prevention and treatment of periodontal diseases” said Dr. Xuesong He, a researcher at the Forsyth Institute and the co-first author on this study.

Additional co-authors of the research include Batbileg Bor and Lujia Cen, both from the Forsyth Institute; Feng Li, Kikuye Koyano, Xinshu “Grace” Xiao and Feng Li from Hunan University of Chinese Medicine. Feng Li also conducts research at the UCLA School of Dentistry.

This research was supported by grants from the National Institute of Dental and Craniofacial Research and from the National Institutes of Health.

Wong is co-founder of RNAmeTRIX Inc., a molecular diagnostic company. He holds equity in RNAmeTRIX and serves as a company director and scientific advisor. The University of California also holds equity in RNAmeTRIX. Intellectual property that David Wong invented and which was patented by the University of California has been licensed to RNAmeTRIX. Wong also is a consultant to GlaxoSmithKline, PeriRx, Wrigley and Colgate-Palmolive. Shi is the founding scientist of C3J Therapeutics, Inc., which has licensed technologies from UC Regents that could be indirectly related to this research project.

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