In situ proliferation and differentiation of macrophages in dental pulp

The presence of macrophages in dental pulp is well known. However, whether these macrophages proliferate and differentiate in the dental pulp in situ, or whether they constantly migrate from the blood stream into the dental pulp remains unknown. We have examined and compared the development of dental pulp macrophages in an organ culture system with in vivo tooth organs to clarify the developmental mechanism of these macrophages. The first mandibular molar tooth organs from ICR mice aged between 16 days of gestation (E16) to 5 days postnatally were used for in vivo experiments. Those from E16 were cultured for up to 14 days with or without 10% fetal bovine serum. Dental pulp tissues were analyzed with immunohistochemistry to detect the macrophages and with reverse transcription and the polymerase chain reaction (RT-PCR) for the detection of factors related to macrophage development. The growth curves for the in vivo and in vitro cultured cells revealed similar numbers of F4/80-positive macrophages in the dental pulp. RT-PCR analysis indicated the constant expression of myeloid colony-stimulating factor (M-CSF) in both in-vivo- and in-vitro-cultured dental pulp tissues. Anti-M-CSF antibodies significantly inhibited the increase in the number of macrophages in the dental pulp. These results suggest that (1) most of the dental pulp macrophages proliferate and differentiate in the dental pulp without a supply of precursor cells from the blood stream, (2) M-CSF might be a candidate molecule for dental pulp macrophage development, and (3) serum factors might not directly affect the development of macrophages

Discoloration of Coating Resins Exposed to Staining Solution: The Influence of Different Surface Conditions

This study evaluates in vitro the effects of discoloration induced by coating resins under various polymerization conditions. Two coating resins (WTC and BTC) were used. Disk specimens (diameter: 15.0 mm;thickness: 0.7 mm) were used uncoated, coated with a polyethylene film, or coated with an application of TopCoat for WTC or GlossRefine for BTC. Five specimens were immersed for 72 h in a staining solution of either coffee or water. The CIELAB coordinates (L*, a*, b*) of each specimen were measured against a black background using a colorimeter (Shade Eye, NCC) and the color difference [ΔE] was estimated and analyzed by one-way ANOVA and Tukey comparison. The specimen surfaces were observed by FE-SEM. The results reveal that for both materials, the uncoated group had the highest ΔE values (p3.6). Coffee discolored the coating resins. Oxygen inhibition significantly affected the discoloration of the coating resins. We propose applying a coating agent for WTC and a glazing agent for BTC to suppress discoloration of coating resins

Morphometrical, Histological and Ultrastructural Analyses of Bone Formation and Resorption Induced by Synthetic Octacalcium Phosphate in Mouse Bone Marrow

Objective: Octacalcium phosphate (OCP) is thought to be a precursor of the mineral crystals in biological apatite. Synthetic OCP has been shown to be converted into an apatite structure when implanted in murine calvarial bone, to enhance bone regeneration. This study was designed to investigate whether OCP implantation enhances the formation and resorption of new bone when implanted intramedullary in a mouse bone marrow.Design: Histological and ultrastructural analyses of bone formation and resorption after 2, 4 and 6 weeks implantation was investigated. MicroCT analysis was also applied to detect the amount of newly formed bone mass after implantation.Results: Massive bone formation on OCP was detected at 2 weeks. Then, the amount of bone was decreased gradually until 6weeks. At 4 and 6 weeks, many multinucleated giant cells, including tartrate-resistant acid phosphatase (TRAP)-positive cells, were detected on the newly formed bone and synthetic OCP. Ultrastructural study indicated that the multinucleated giant cells attached either to the bone and OCP surface were osteoclasts forming the clear zones and ruffled borders composed of finger-type and platetype cell processes. However, the ultrastructure of cell processes in ruffled borders showed the irregular shape. No representative cell processes were detected in the cells.Conclusion: These results confirmed the active induction of bone formation and resorption on OCP and also suggested that the structure of ruffled border might be regulated by the target calcified materials

How reliable are failure site assessments after "macro" shear debonding of resin from tooth substrate?

Objective: To determine inter-examiner reliability and concordance of failure pattern assessments made by stereomicroscopy and SEM, respectively, after macro shear bond testing of bonded resin composite from human enamel and dentin.Method: Six investigators examined independently the failure pattern morphology of 184 debonded tooth side specimens using stereomicroscopy inspection at 20-fold magnification. The same specimens were investigated using SEM at 1000-fold magnification to determine the "true" failure site morphology. Failures were classified as 1=adhesive, 2=mixed (adhesive-cohesive), 3=cohesive in resin, 4=cohesive in tooth, 5=mixed cohesive (resin-tooth).Results: Spearman’s rho coefficients of correlation between the paired examiner score allocations differed between "strong disagreement" and "moderate agreement". Comparisons of each examiner's ratings with the SEM ratings revealed coefficients, describing these relationships as“disagreement"in the worst and“moderate agreement" in the best case.Conclusion: Inter-examiner reliability in fracture pattern characterization of tooth specimens is ambiguous and not concordant with fracture pattern morphology rating using SEM

The Detection and Negative Reversion of Circulating Tumor Cells as Prognostic Biomarkers for Metastatic Castration-Resistant Prostate Cancer with Bone Metastases Treated by Enzalutamide

Enzalutamide is a second-generation androgen receptor inhibitor that increases overall survival (OS) rates in patients with metastatic castration-resistant prostate cancer (mCRPC). This study evaluates the efficacy of circulating tumor cell (CTC) status as a prognostic biomarker following enzalutamide administration. A retrospective subgroup analysis and prognostic survey were conducted on 43 patients with mCRPC and bone metastases treated in Juntendo University-affiliated hospitals from 2015 to 2022. Patients were treated with 160 mg enzalutamide daily. CTC analyses on blood samples were performed regularly before and every three months after treatment. The relationship between the patients’ clinical factors and the OS rate was analyzed using the log-rank test; the median OS was 37 months. Patients with no detected CTCs at baseline showed significantly longer OS than those with detectable CTCs at baseline. Furthermore, patients demonstrating negative reversion of CTCs during enzalutamide treatment had significantly longer OS than patients with CTC-positivity. Two biomarkers—higher hemoglobin at baseline and achieving negative reversion of CTCs—were significantly associated with prolonged OS. This study suggests that patients achieving CTC-negative reversion during treatment for mCRPC with bone metastases exhibit improved long-term OS. Chronological measurement of CTC status might be clinically useful in the treatment of mCRPC