|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1995 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1994 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Candidates stimulators of bone resorption that have been proposed include bacterial components such as lipopolysacharide, prostaglandins, bradykinin, antigen-antibody complexes, and inflammatory cytokines produced by host cells in response to the infection. Inflammatory cytokinesare of particular interest because they are strongly expressed by many host types in response to bacterial infection and they are potent stimulators of bone resorption.
To determine the type of inflammatory cytokines associated with active lesion formation, a molecular biological study was carried out to identify genes. Cytokine gene expression has been analyzed at the level of mRNA.mRNA for inflammatory cytokines was amplified by reverse transcription polymerase chain reaction (RT-PCR).
To identify the bone-destructive mediators, I have analyzed extracts of periapical tissues and periapical exudate cells.
The results were as follows :
1. Immunohistologically, the majority of the T cells infiltrating the periapical lesions was reactive with anti-CD4 antibody.
2. Remarkably high expressions of IL-beta and TNF were observed in all periapical lesions.
3. The expressions of IL-1 alpha, IL-1 beta and TNF were detected in the cells of periapical exudate by RT-PCR assay. The high levels of IL-1 beta correlate with acute apical periodontitis. In addition, when IL-1 alpha and IL-1 beta expressions were compared, IL-1 beta ones were found to be greater than IL-1 alpha ones.