Mirdza E. Neiders

Rapid Identification of Periodontal Pathogens in Subgingival Plaque: Comparison of Indirect Immunofluorescence Microscopy with Bacterial Culture for Detection of Actinobacillus actinomycetemcomitans

The sensitivity of indirect immunofluorescence microscopy using specific polyclonal or monoclonal serodiagnostic reagents for Actinobacillus actinomycetemcomitans in subgingival dental plaque ranged from 82-100% as compared with culture on selective or non-selective media. This bacterium was found in 100% of the periodontally diseased sites examined in localized juvenile periodontitis patients and was statistically related to clinical indices of periodontal disease including the Gingival Index, Plaque Index, and Pocket Depth. Indirect immunofluorescence microscopy is a useful technique for the rapid and reliable determination of A. actinomycetemcomitans in human subgingival dental plaque which may be applied to the clinical diagnosis, treatment, and monitoring of periodontitis associated with A. actinomycetemcomitans.

Collagen as an Implantable Material in Medicine and Dentistry

Collagen is a highly versatile material, extensively used in the medical, dental, and pharmacological fields. Collagen is capable of being prepared into cross-linked compacted solids or into lattice-like gels. Resorbable forms of collagen have been used to dress oral wounds, for closure of graft and extraction sites, and to promote healing. Collagen-based membranes also have been used in periodontal and implant therapy as barriers to prevent epithelial migration and allow cells with regenerative capacity to repopulate the defect area. It has been hypothesized that membrane regenerative techniques facilitate the natural biological potential by creating a favorable environment for periodontal and peri-implant regeneration. Due to the enormous potential of collagen-based regenerative barriers, clinicians may benefit from a review of potential applications of implantable collagen and knowledge of collagen preparation and membrane types as well as from as awareness of the functional and degradation properties of those materials.

Collagen: an overview.

Collagen is a versatile material with biological properties that make it useful for the fabrication of implantable devices in medicine and dentistry. In this article we review collagen biosynthesis, structure, and types, as well as the properties that make it compatible with human tissues.

Electron Probe Microanalysis of Cementum and Underlying Dentin in Young Permanent Teeth

The amount of calcium, phosphorus, and magnesium in human cementum and subjacent dentin of young permanent teeth was studied with the use of an electron probe microanalyzer and was correlated with morphology with the use of a scanning electron microscope. The mineral content of the cementum and the granular layer of Tomes was significantly lower than that of tubular dentin and the hypermineralized zone.

Chronic ulcerative stomatitis: clinical, histopathologic, and immunopathologic findings.

Chronic ulcerative stomatitis (CUS) is a mucocutaneous disease primarily involving mucosal surfaces, but occasionally may involve the skin. Clinically, CUS patients exhibit erosive or ulcerative lesions of the oral mucosa that resemble erosive oral lichen planus. Direct immunofluorescence (DIF) studies of mucosal or skin biopsies reveal a unique pattern of IgG immunoglobulin bound to nuclei of keratinocytes of the basal and lower one third cell layers, the stratified epithelial specific (SES) antinuclear antibody (ANA) pattern. Patient sera also exhibit circulating SES-ANA reactions on indirect immunofluorescence (IIF) using an esophagus substrate. We report the clinical and immunopathologic findings of 3 cases of CUS and demonstrate autoantibody recognition of the CUS antigen on Western blot. An important reason to distinguish CUS from other oral ulcerative conditions is that it may be refractory to standard treatments with topical corticosteroids, and favorable clinical responses may be achieved with hydroxychloroquine pharmacotherapy.

Effect of protoporphyrin IX limitation on Porphyromonas gingivalis

Porphyromonas gingivalis has been shown to require hemin or hemoglobin for in vitro growth. We have previously shown that protoporphyrin IX and inorganic iron can replace the hemin requirement, suggesting that the hemin requirement of this microorganism is actually a porphyrin requirement. We examined the effect of protoporphyrin IX limitation to P. gingivalis strain A7A1-28 in the presence of sufficient iron on growth characteristics, proteolytic enzyme production, virulence in a mouse abscess model, and expression of membrane proteins. Bacterial cells were grown in medium varying between 0 to 5 microM reduced growth by at least 50%. Protoporphyrin IX availability did not affect proteolytic enzyme production or virulence in a mouse abscess model. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of membrane preparations demonstrated that protoporphyrin IX limitation induced the expression of new proteins at 42, 34, 30, 29, and 18 kDa and suppressed the production of proteins at 47, 27, 17, and 15 kDa. These studies suggest that in vivo protoporphyrin availability may modulate membrane protein expression and in turn affect host immune responses against P. gingivalis.

Immunochemistry and immunogenicity of low molecular weight human salivary mucin

The purposes of this study were to examine the immunogenicity of the low molecular weight human salivary mucin (MG2) and determine its distribution within major and minor human salivary glands. Anti-MG2 sera were produced in Balb/c mice by a variety of immunization schedules. Chromatographically or electrophoretically purified MG2 and partially purified mucin chromatographic fractions exposed to mild denaturing conditions were not immunogenic. Only MG2 without prior exposure to urea or guanidine was able to elicit an immune response. A murine anti-MG2 monoclonal antibody (clone 1/F9) was produced and its monospecificity confirmed by immuno-dot blotting and SDS-PAGE Western transfer. Clone 1/F9 (IgG1; kappa) was of moderate affinity and was directed to a Pronase- and TPCK trypsin-sensitive but periodate-resistant epitope which was not blood group- or sialic acid-specific. Immunocytochemical studies of frozen tissue sections with clone 1/F9 using both indirect and direct methods revealed that MG2 was more heterogeneously distributed within submandibular than labial glands and was not found in parotid or palatine glands. The use of a polyclonal rabbit anti-MG2 reagent in either frozen or paraffin-embedded tissues gave the same immunocytochemical results as those obtained with the monoclonal antibody.

Immunochemistry of high molecular-weight human salivary mucin

The purpose of this study was to determine the distribution of mucin glycoprotein 1 (MG1) within submandibular, parotid, labial and palatine salivary tissues. Formalin-fixed and frozen tissue sections were examined histochemically with PAS, Alcian blue and Meyers mucicarmine, and immunocytochemically with an anti-mucin glycoprotein 1 monoclonal antibody (clone 3/E8). Clone 3/E8 was produced in Balb/c mice using mucin-enriched chromatographic fractions from submandibular-sublingual saliva. The monospecificity of 3/E8 was confirmed by immuno-dot blotting and SDS-PAGE/electrophoretic transfer. Clone 3/E8 (IgG1; kappa) was of moderate affinity, and was directed to a carbohydrate-containing, TPCK-trypsin-insensitive and pronase-insensitive epitope on this mucin, which was not blood-group specific. The location of mucin glycoprotein 1 was determined by both indirect (peroxidase-antiperoxidase) and direct methods. Mucin glycoprotein 1 was localized within all labial acini examined, but was not found within parotid tissues. Histochemical methods stained all submandibular, palatine and labial acini, but immunocytochemistry with monoclonal antibody revealed heterogeneous staining with clone 3/E8 in submandibular and palatine tissues. These findings suggest the presence of mucin glycoprotein 1-specific acinar cell subpopulations within human submandibular and palatine salivary tissues.

Inorganic Components of the Peritubular Dentin in Young Human Permanent Teeth

Six premolar teeth, from patients aged11 to 15 years, were used in a study of peritubular and intertubular dentin in the crown and root. Anelectron microprobe with an associated scanning electron micr

Autoimmunity to deltaNp63alpha in Chronic Ulcerative Stomatitis

Chronic ulcerative stomatitis (CUS) is a recently described mucocutaneous condition in which patients experience chronic, painful, ulcerative lesions of the oral mucosa. CUS is diagnosed by immunofluorescence studies that demonstrate antinuclear antibodies. These autoantibodies are specific for a protein, deltaNp63alpha, which is normally expressed in basal cell nuclei of stratified squamous epithelia. The purpose of this study was to characterize the autoimmune response in CUS. Protein antigens were produced by in vitro transcription/translation of polymerase chain-reaction (PCR)-amplified cDNAs. We used immunoblotting and immunoprecipitation experiments with serum from CUS patients to examine the (1) antibody isotype, (2) immunogenic functional domains of the deltaNp63alpha antigen, and (3) cross-reactivity with homologous p53, p73, and p63 proteins. Results demonstrate CUS patient antibodies to deltaNp63alpha, and 52% of cases have circulating IgA isotype antibodies. The N-terminal and DNA-binding domains are the immunodominant regions, and antibody cross-reactivity with p53, p63, and p73 isoforms is limited.