Related items
Showing items related by title, author, creator and subject.
-
Periodontal, metabolic, and cardiovascular disease: Exploring the role of inflammation and mental healthPrevious evidence connects periodontal disease, a modifiable condition affecting a majority of Americans, with metabolic and cardiovascular morbidity and mortality. This review focuses on the likely mediation of these associations by immune activation and their potential interactions with mental illness. Future longitudinal, and ideally interventional studies, should focus on reciprocal interactions and cascading effects, as well as points for effective preventative and therapeutic interventions across diagnostic domains to reduce morbidity, mortality and improve quality of life. Copyright 2018 Hina Makkar et al.
-
In vitro production of human antibodies reactive with periodontal pathogens, using Epstein-Barr virus immortalization of B lymphocytes derived from peripheral blood of periodontal patients, with an emphasis on the production of a human monoclonal antibody reactive with the heat-modifiable outer membrane protein of Actinobacillus actinomycetemcomitansThe purpose of this research was to develop cell line(s) that produce a human monoclonal antibody (huMAb) specific to an oral pathogenic microorganism using Epstein-Barr virus (EBV) transformation of B cells isolated from the gingiva and the peripheral blood of periodontal patients with active disease. The resulting huMAB was then characterized. Excised gingival tissue was obtained from 6 patients and peripheral blood was obtained from 3 of the same patients. To release cells, the gingival tissue was digested with collagenase. Gingival mononuclear cells (GMC) and peripheral blood mononuclear cells (PBMC) were then separated from the gingival extracts, patient peripheral blood, and leukophoresed blood from an anonymous donor by Ficoll centrifugation. The resulting cells were infected with EBV, cultured in 96-well plates, and observed for foci of transformation. Using a dot-immunobinding assay (DIB), the cell culture supernatant fluids (CCS) of transformation-positive wells were tested for Ab reactivity to a panel of 11 microorganisms. Continuously positive cultures were expanded and cloned by limiting dilution. Using an ELISA, clone CCS was tested for Ab reactivity to the microorganism to which the originating culture had exhibited reactivity (target organism). Positive responders were expanded and retested with the ELISA. Continuously producing clones were expanded further, CCS was collected, and excess cells were cryopreserved. The class of Ab in each CCS was determined with a DIB, IgG subclasses and concentration were determined with a commercial ELISA, and the light chain type was determined with a fixed cell indirect immunofluorescence assay (IFA). Using representative strains of the target microorganism, Western blots were performed (separation of bacterial proteins by SDS-PAGE, electroblotting onto nitrocellulose, and probing with concentrated CCS) to determine the MW of the band(s) to which the human antibodies (huAbs) bound. To exclude the possibility of non-specific Ig binding by the target organism, a Western blot was performed with a huMAb of the same IgG subclass and light chain type but with specificity toward a viral protein.;GMC did not transform. Of 517 wells receiving PBMC, 503 wells (97%) had foci of transformation. CCS from 71 of the 517 (14%) wells initially tested positive for Ab activity, most commonly to Eikenella corrodens, Actinobacillus actinomycetemcomitans (Aa), Bacteroides fragilis, Peptostreptococcus micros, and Campylobacter rectus, in order of decreasing frequency. Subsequent DIB during expansion of the cells demonstrated 28, 12, 7, 3, and finally 1 culture with Ab activity (II-24P, reactive with Aa ATCC 43718).;A similar (pilot) experiment was performed with PBMC from 2 healthy control volunteers and from leukophoresed blood. Although initial Ab-producing cultures were obtained, none of the clones produced significant amounts of Ab. (Abstract shortened by UMI).
-
The non-linear stress-strain behavior of the human periodontal ligament and its effect on finite element models of dental structuresFresh and fixed mandibular block sections were acquired from cadavers. The block sections were then sectioned to create small (1 x 1 x 4mm) uniaxial tests specimens containing tooth, PDL, and bone. Specimens were then tested in a mechanical test system to acquire load-displacement and stress-strain data. Samples were also prepared for scanning electron microscope (SEM) evaluation and PDL space variability measurements. Stress-strain data was then incorporated into FE models for analysis of model effects. Stress-strain curves of fixed and unfixed tissue indicate the PDL is highly non-linear and inelastic in its behavior. The curves are described by power functions, exhibit greater hysteresis in compression than tension, and the zero stress-strain state is shifted towards the compressive side of the curve. SEM evaluations show the PDL to be very complex three-dimensionally, with a highly branching and interweaving fiber bundle structure. The PDL space was found to vary widely in its thickness, with standard deviations as high as 53% of the mean value for a given tooth level. FE models with non-linear PDL data show vastly different stress distribution patterns when compared to linear PDL models. Stress-strain curves, as well as FE models that incorporate the measured materials behavior, suggest that the primary load carrying ability of the PDL is in compression. The non-linear nature of the PDL also results in higher compressive stresses being generated, for both lateral and axial loading, than a comparable linear model. SEM evaluation suggests that PDL fibers may function in compression by layering on top of each other. Using non-linear analysis of the PDL, the location of the center of resistance (CR) of a tooth was found to vary horizontally and vertically depending on the applied loading and PDL geometry. The shifting of CR away from the midline indicates that orthodontic tipping about a root apex may actually be impossible. The PDL was also found to be subjected to compression over the entire PDL when intrusive loading was applied to the tooth. This may explain how occlusal trauma can widen the entire PDL.