ABSTRACT
OBJECTIVE: Actinomycosis infection of bone is rare and its diagnosis challenging. Here, we aim to identify and verify its microstructural features and the potential value for differential diagnosis. MATERIALS: We investigated the dry preparation of the lumbar vertebrae and pelvic ring of a purported case of actinomycosis documented by a post-mortem examination in 1891. METHODS: Macroscopic inspection, conventional radiology, µCT, 3D reconstruction, and histological examination were employed. RESULTS: All approaches revealed new periosteal bone deposition with increased vascularisation of the os coxa, vertebrae, and sacrum. The µCT revealed cortical loss underneath the new bone formation; the 3D reconstruction and histological examination revealed plexiform bone and granular structures. CONCLUSIONS: The plexiform bone is the result of reactive rapid growth and remodelling processes, and is consistent with pathomorphological findings summarised in the autopsy report (soft tissue abscesses and formation of fistulas caused by "Actinomycosis intestine et ossis ilei sin."). SIGNIFICANCE: This is the first case of a historically documented case of actinomycosis infection investigated by µCT and histology. Different degrees of tissue damage and inflammatory reaction in form of plexiform bone, which has not been reported previously, was identified. LIMITATIONS: The noted bone tissue modifications are not solely pathognomic of actinomycosis; they characterise other diseases, as well. Histological evaluation is not appropriate for identifying the aetiology of the granular structures observed here; but clinically such aggregations appear in tissue affected by actinomycosis. SUGGESTIONS FOR FURTHER RESEARCH: Histochemical and molecular-genetic analyses are obligatory to affirm the diagnosis based on micromorphological features.
Subject(s)
Actinomycosis , Lumbar Vertebrae , Pelvic Bones , Actinomycosis/diagnostic imaging , Actinomycosis/history , Actinomycosis/pathology , Adult , Female , History, 19th Century , Humans , Imaging, Three-Dimensional , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/pathology , Paleopathology , Pelvic Bones/diagnostic imaging , Pelvic Bones/pathology , X-Ray Microtomography , Young AdultABSTRACT
BACKGROUND AND OBJECTIVE: In regenerative dentistry, platelet preparations are applied to stimulate bone healing and periodontal regeneration. Here, we pursue a strategy where bone substitutes are used as carriers for platelet-released supernatants. The mitogenic capacity and release kinetics of loaded bone substitutes were assessed. MATERIAL AND METHODS: Platelet-released supernatants of washed platelets (washed PRS) and platelet-released supernatants of unwashed platelets (unwashed PRS) were lyophilized onto the bone substitutes deproteinized bovine bone mineral, hydroxyapatite and ß-tricalcium phosphate. Scanning electron microscopy images were taken. Supernatants of bone substitutes were collected at hours 1, 3, 6, 24, and 48 and medium was replaced. We evaluated the protein content with the bicinchoninic acid assay and the effect on proliferation using bioassays with human periodontal fibroblasts. Release of growth factors from the loaded bone substitutes was measured based on the platelet-derived growth factor isoform (PDGF-BB) and thrombin immunoassays. Furthermore, we assessed DNA and RNA content of washed PRS and unwashed PRS. RESULTS: Unwashed PRS showed higher total protein concentrations than washed PRS, while the concentration of PDGF-BB, thrombin, DNA, RNA and their mitogenic effect was not significantly different. The bone substitute materials adsorbed protein over time but no significant changes in overall appearance was found. Supernatants collected from unwashed PRS-loaded bone substitute after 1 h induced a potent mitogenic response in periodontal fibroblasts. This pro-mitogenic capacity of the supernatants decreased over the observation period. Supernatants of washed PRS-loaded bone substitutes did not induce a substantial mitogenic effect. Levels of PDGF-BB, thrombin and protein were higher in supernatants of unwashed PRS-loaded bone substitutes than of washed PRS-loaded bone substitutes. CONCLUSION: Bone substitutes loaded with unwashed PRS, but not bone substitutes loaded with washed PRS show continuously declining release kinetics. These data suggest that plasma components in platelet preparations can modify the release kinetics profile.
