Restriction fragment-length polymorphism analysis of 16S ribosomal RNA genes amplified by polymerase chain reaction for rapid identification of cultivable oral treponemes.

Although oral treponemes are among the most frequently found bacteria in periodontal pockets, identification of these organisms can be difficult. In this study, restriction fragment-length polymorphism (RFLP) analysis of polymerase chain reaction (PCR)-amplified 16S ribosomal RNA genes (16S rRNA gene PCR-RFLP) was used to generate restriction profiles of reference strains of oral treponemes including Treponema denticola, Treponema socranskii, Treponema vincentii. Treponema pectinovorum and Treponema medium as well as for Treponema phagedenis and Treponema pailidum and five treponeme strains isolated from human peridontal pockets.

Saliva: a convenient source of DNA for analysis of bi-allelic polymorphisms of Fc gamma receptor IIA (CD32) and Fc gamma receptor IIIB (CD16).

Genetic polymorphisms of low-affinity IgG Fc receptors (Fc gamma R) have been found to influence binding of human IgG subclass antibodies, and may influence susceptibility to certain types of infectious and autoimmune diseases. Phenotypic and/or genotypic analyses of Fc gamma R polymorphisms have traditionally employed peripheral venous blood as a source of leukocytes or genomic DNA, respectively. The present study was undertaken to determine whether human salivary DNA is a suitable alternative to DNA extracted from blood for genetic analysis of FC gamma R allelic polymorphisms.

The relationship between radiographic and clinical changes in the periodontium.

Change in clinical attachment level (CAL) and radiographic change in crestal bone height are often used to assess periodontal breakdown and disease progression. These two variables are also used to monitor the effect of treatment. The purpose of the present longitudinal study was to evaluate the correlation between changes in CAL and alveolar bone loss.

Mapping of the extracellular binding regions of the human interleukin-8 type B receptor.

This study was undertaken to define the regions of the human interleukin-8 type B receptor (IL8RB) which are critical for binding the ligands interleukin-8, NAP-2 and GRO alpha. Peptides corresponding to the N-terminus region and the first extracellular loop of the receptor demonstrated statistically significant (p = 0.001) inhibition of IL-8 control binding levels (inhibition levels of 73.

Isolation and characterization of a hemin-regulated gene, hemR, from Porphyromonas gingivalis.

An hemR (hemin-regulated) gene from Porphyromonas gingivalis ATCC 53977 has been isolated and characterized. This gene is present downstream from the prtT gene, previously cloned in this laboratory. In addition, another putative gene, ORF1, was identified between hemR and prtT.

Isolation and preliminary characterization of the Streptococcus mutans rpsJ gene.

We previously reported that four putative open reading frames were identified in the regions flanking the Streptococcus mutans GS-5 fructosyltransferase gene. For one of these, ORF 4, only a small region had been isolated and the first 30 nucleotides had been sequenced. In order to determine whether this open reading frame is part of an expressed gene, we isolated a DNA fragment containing intact ORF 4 and a portion of the downstream ORF 5 by inverse polymerase chain reaction.

Porphyromonas gingivalis surface components induce interleukin-1 release and tyrosine phosphorylation in macrophages.

The aim of the present study was to characterize the responses of macrophages to surface antigens of Porphyromonas gingivalis. Native fimbriae, full-length recombinant fimbrillin, and a lectin-like 12-kDa antigen all stimulated BALB/c peritoneal macrophages to secrete interleukin (IL)-1 beta. The antigens induced similar patterns of tyrosine phosphorylation; proteins in approximately 35-46 kDa range of undetermined identities were phosphorylated in the macrophages.

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.

Identification of the Streptococcus mutans frp gene as a potential regulator of fructosyltransferase expression.

Four putative open reading frames (ORFs) were previously identified in the regions flanking the Streptococcus mutans GS-5 fructosyltransferase (FTF) gene. One of these, ORF 3, appeared to code for a low-molecular-mass protein containing amino acid sequences sharing homology with several Gram-positive bacterial DNA-binding proteins and it was suggested that the ORF 3 gene product might be an FTF regulatory protein (FRP). In order to characterize this protein, we have purified the biotinylated tag-FRP fusion protein using the PinPoint protein purification system and this fusion protein was used in gel shift assays with DNA fragments containing the ftf promoter region.

Identification of linear antigenic sites on the Porphyromonas gingivalis 43-kDa fimbrillin subunit.

The fimbrillin of Porphyromonas gingivalis is thought to be an important virulence factor that mediates adherence to host surfaces. The linear immunogenic and antigenic structure of P. gingivalis fimbrillin was investigated with synthetic peptides corresponding to the amino acid sequence predicted from the cloned fimbrillin gene for P.

Mandible bone resorption as determined from panoramic radiographs in edentulous male individuals ages 25-80 years.

Routine panoramic radiographs of 173 healthy edentulous males, aged 25-80 years, were measured for estimated bone loss using the Wical and Swoope (1974) technique. Results using this simple technique were comparable to other studies using more sophisticated methods but did not require exposure to additional radiation. Mean ratios of height of mandible (indicative of mandibular bone loss) decreased both with age of subject and with time after extraction.

Cloning and sequence analysis of a chymotrypsinlike protease from Treponema denticola.

A clone expressing a Treponema denticola chymotrypsinlike protease from recombinant plasmid pSA2 was identified in a genomic library of T. denticola ATCC 35405. Nucleotide sequencing of the insert identified an open reading frame, designated the prtB gene, which codes for the protease.

Membrane protein expression by Actinobacillus actinomycetemcomitans in response to iron availability.

Iron-limited growth conditions under anaerobiosis were established for Actinobacillus actinomycetemcomitans strains Y4, JP2, and 75 by use of the ferrous ion chelator 2,2'-dipyridyl. Growth inhibition was reversible with both ferrous and ferric iron sources. Sarcosyl-insoluble membrane fractions of iron-stressed anaerobic A.