Evaluating levels of dentist participation in Medicaid: A complicated endeavor.

BACKGROUND: The availability of dentists to care for Medicaid beneficiaries is a longstanding concern of many families and those who serve them in the dental profession as well as policy makers. Yet, little information beyond the number of enrolled dentists has been reliably determined. The American Dental Association (ADA) Health Policy Institute has called for more nuanced measures that better reflect dentistry's contribution to the care of Medicaid beneficiaries. METHODS: The authors calculated percentages of general and pediatric dentists who enrolled in Medicaid, billed Medicaid, and treated Medicaid beneficiaries in each state for which data were available from the ADA's 2008 study, the Association of State and Territorial Dental Directors' 2013 report, and the 2013 federal Web site InsureKidsNow.org. To determine the number of primary dentists available to treat Medicaid beneficiaries, the ADA masterfile list of clinically active dentists was adjusted to remove nonpediatric dental specialists. RESULTS: The authors determined that the ADA's 2015 analysis of dentists enrolled in Medicaid was the most rigorously assessed source for enrollment but did not report numbers of billing or treating dentists. Increasingly stringent metrics of participation are associated with considerable declines in dentist participation. They found the underlying data sources unreliable, inaccurate, and incomparable within and among states. CONCLUSIONS: The authors concluded that no consistent, comparable, ongoing source of dentist participation in Medicaid exists that reliably provides substantive information to the profession and policy makers. PRACTICAL IMPLICATIONS: Dentistry's ability to respond to policymakers' concerns about service to Medicaid beneficiaries depends on the development and implementation of a standardized, reliable, systematic, and ongoing method to measure meaningful participation.

An Arabidopsis cell wall proteoglycan consists of pectin and arabinoxylan covalently linked to an arabinogalactan protein.

Plant cell walls are comprised largely of the polysaccharides cellulose, hemicellulose, and pectin, along with ∼10% protein and up to 40% lignin. These wall polymers interact covalently and noncovalently to form the functional cell wall. Characterized cross-links in the wall include covalent linkages between wall glycoprotein extensins between rhamnogalacturonan II monomer domains and between polysaccharides and lignin phenolic residues. Here, we show that two isoforms of a purified Arabidopsis thaliana arabinogalactan protein (AGP) encoded by hydroxyproline-rich glycoprotein family protein gene At3g45230 are covalently attached to wall matrix hemicellulosic and pectic polysaccharides, with rhamnogalacturonan I (RG I)/homogalacturonan linked to the rhamnosyl residue in the arabinogalactan (AG) of the AGP and with arabinoxylan attached to either a rhamnosyl residue in the RG I domain or directly to an arabinosyl residue in the AG glycan domain. The existence of this wall structure, named ARABINOXYLAN PECTIN ARABINOGALACTAN PROTEIN1 (APAP1), is contrary to prevailing cell wall models that depict separate protein, pectin, and hemicellulose polysaccharide networks. The modified sugar composition and increased extractability of pectin and xylan immunoreactive epitopes in apap1 mutant aerial biomass support a role for the APAP1 proteoglycan in plant wall architecture and function.