Aim
To assess whether Epstein–Barr virus (EBV) reactivation is triggered by persistent apical periodontitis‐related microbes using in vitro and ex vivo methodologies.
Methodology
Surgically removed ...human periapical granulomas (n = 50) and healthy gingival tissues (n = 10) were analysed to determine the presence of EBV and seven persistent apical periodontitis‐related microbes. In addition, real‐time polymerase chain reaction was used to detect the mRNA expression of BZLF‐1, an immediate–early gene of EBV. Expression of latent membrane protein (LMP)‐1 and ZEBRA, an early lytic protein of EBV encoded by BZLF‐1, was also examined using triple‐colour immunofluorescence staining. n‐Butyric acid produced by the microbes was quantified, and luciferase assays were performed in association with bacterial lysates. In addition, Daudi cells were cultured with bacterial lysates, and the expression levels of BZLF‐1 mRNA and ZEBRA protein were determined.
Results
EBV DNA and BZLF‐1 mRNA were detected in 47 out of 50 periapical granulomas, but not in healthy gingival tissues. The EBV DNA copy number and the number of Fusobacterium nucleatum were significantly positively correlated with BZLF‐1 expression in periapical granulomas. The number of Prevotella intermedia was slightly correlated with BZLF‐1 expression; however, the other microbes were not. CD79a‐positive B cells in periapical granulomas, but not those in healthy gingival tissues, expressed both LMP‐1 and ZEBRA. n‐Butyric acid production was the highest in F. nucleatum and the lowest in P. intermedia. Enterococcus faecalis, Candida albicans and the other tested microbes did not produce n‐butyric acid. An F. nucleatum lysate exhibited significantly increased BZLF‐1‐luciferase activity in the same manner of commercial butyric acid, whereas P. intermedia did not. F. nucleatum also induced the expression of BZLF‐1 mRNA and ZEBRA protein by Daudi cells, indicating that EBV reactivation was induced.
Conclusion
Among the persistent apical periodontitis‐related bacteria that were tested, F. nucleatum most strongly reactivated latent EBV, whereas E. faecalis and C. albicans as well as the other microbes did not.
Aim
To determine whether Porphyromonas endodontalis can reactivate latent Epstein–Barr virus (EBV).
Methodology
The concentrations of short‐chain fatty acids (SCFAs) in P. endodontalis culture ...supernatants were determined using high‐performance liquid chromatography. A promoter region of BamHI fragment Z leftward open reading frame 1 (BZLF‐1), which is a transcription factor that controls the EBV lytic cycle, was cloned into luciferase expression vectors. Then, the luciferase assay was performed using P. endodontalis culture supernatants. Histone acetylation using Daudi cells treated with P. endodontalis culture supernatants was examined using Western blotting. BZLF‐1 mRNA and BamHI fragment Z EB replication activator (ZEBRA) protein were also detected quantitatively using real‐time polymerase chain reaction (PCR) and Western blotting. Surgically removed periapical granulomas were examined to detect P. endodontalis, EBV DNA, and BZLF‐1 mRNA expression using quantitative real‐time PCR. Statistical analysis using Steel tests was performed.
Results
The concentrations of n‐butyric acid in P. endodontalis culture supernatants were significantly higher than those of other SCFAs (P = 0.0173). Using B‐95‐8‐221 Luc cells treated with P. endodontalis culture supernatants, the luciferase assay demonstrated that P. endodontalis induced BZLF‐1 expression. Hyperacetylation of histones was also observed with the culture supernatants. BZLF‐1 mRNA and ZEBRA protein were expressed by Daudi cells in a dose‐dependent manner after the treatment with P. endodontalis culture supernatants. P. endodontalis and BZLF‐1 in periapical granulomas were also detected. The expression levels of BZLF‐1 mRNA were similar to the numbers of P. endodontalis cells in each specimen.
Conclusions
n‐butyric acid produced by P. endodontalis reactivated latent EBV.
Aim
To investigate the role played by silent information regulator 2 homologue 1 (SIRT1) during angiogenesis of periapical periodontitis.
Methodology
Periapical granulomas were subjected to ...dual‐colour immunofluorescence imaging and real‐time polymerase chain reactions assaying the expression levels of SIRT1, vascular endothelial growth factor (VEGF) and VE‐cadherin. The association between Ki‐67 and SIRT1 expression was also examined. Human umbilical vein endothelial cells (HUVECs) were treated with a combination of lipopolysaccharide and resveratrol (a SIRT1 activator) or sirtinol (a SIRT1 inhibitor); and the levels of mRNAs encoding SIRT1, VEGF and VE‐cadherin were determined. HUVEC tube formation was assayed in the presence of resveratrol or sirtinol. The Mann–Whitney U‐test or the Tukey–Kramer test was used for statistical analysis.
Results
Ki‐67‐expressing cells, including endothelial cells, lay adjacent to SIRT1‐expressing cells in periapical granulomas. In addition, SIRT1‐expressing cells were detected adjacent to VEGF‐expressing cells and VEGF‐ or VE‐cadherin‐expressing endothelial cells. SIRT1, VEGF and VE‐cadherin mRNA expression levels in periapical granulomas were significantly higher (P = 0.0054, 0.0090 and 0.0090, respectively) than those in healthy gingival tissues. HUVECs treated with resveratrol exhibited significantly higher expression of mRNAs encoding SIRT1, VEGF and VE‐cadherin (P = 0.0019, 0.00005 and 0.0045, respectively) compared with controls, but sirtinol inhibited such expression. Resveratrol caused HUVECs to form tube‐like structures, whilst sirtinol inhibited this process.
Conclusions
These findings suggest that SIRT1 may stimulate angiogenesis in periapical granulomas by triggering the proliferation of endothelial cells and inducing VEGF and VE‐cadherin expression.
We searched for the 6α-condensed state in 24Mg by measuring the C12+12C scattering with the SAKRA Si detector array at Ecm=17.5–25.0 MeV. By using the invariant-mass method for the detected 3α ...particles, the inclusive cross sections for the C12+12C→12C(02+)+X and C12(31−)+X reactions were determined. In addition, the missing-mass spectroscopy was successfully utilized to determine the excitation energy of the residual C12 nucleus and the exclusive cross sections for the C12+12C→12C(02+)+12C(01+), C12(02+)+12C(21+), and C12(02+)+12C(02+) reactions. In both the inclusive C12(02+)+X channel and the exclusive C12(02+)+12C(01+) channel, the cross section peaked at Ecm=19.4 MeV, which correspond to the excitation energy of Ex=33.3 MeV in 24Mg. This 19.4-MeV state is a candidate for the 6α-condensed state because of the agreement of the excitation energy with the theoretical value and its decay property. In the exclusive C12(02+)+12C(02+) channel, a broad state was observed at Ecm=22.5 MeV, which correspond to the excitation energy of Ex=36.4 MeV in 24Mg. From the angular distribution of the differential cross section, the spin and parity of this 22.5-MeV state was assigned to be 4+. In addition, a 2+ state was suggested at the low-energy side of the 22.5-MeV state. Because their excitation energies are higher than the theoretical value of the 6α-condensed state, these states might be excited states of the 6α-condensed state such as the 22+ and 41+ states in C12.
The Co(
m ML)/Ru(
n ML) superlattice systems, where
m and
n are integers (=1–5) and ML means monolayer, show a drastic transition of the Co spin structure, depending on
m and
n: interlayer ...ferromagnetic (F) and antiferromagnetic (AF) spin alignments with perpendicular magnetization. We have succeeded in the observation of magnetic microstructures much different between the F and AF coupled multilayer films by means of magnetic force microscopy. Interconnected and segmented stripe domains, which are typical for a ferromagnetic thin film with perpendicular anisotropy, are observed for the F coupled films with their stripe widths around 80
nm. On the other hand, antiferromagnetically coupled domains (i.e., laterally ferromagnetic domains but with interlayer antiparallel coupling with perpendicular magnetization) are observed for the AF coupled films. The shape of domains for the AF coupled films is rather irregular, and the size exceeds 1
μm typically.
To search for low-energy resonant structures in isospin T=3/2 three-body systems, we have performed the experiments ^{3}H(t,^{3}He)3n and ^{3}He(^{3}He,t)3p at intermediate energies. For the 3n ...experiment, we have newly developed a thick Ti-^{3}H target that has the largest tritium thickness among targets of this type ever made. The 3n experiment for the first time covered the momentum-transfer region as low as 15 MeV/c, which provides ideal conditions for producing fragile systems. However, in the excitation-energy spectra we obtained, we did not observe any distinct peak structures. This is in sharp contrast to tetraneutron spectra. The distributions of the 3n and 3p spectra are found to be similar, except for the displacement in energy due to Coulomb repulsion. Comparisons with theoretical calculations suggest that three-body correlations exist in the 3n and 3p systems, although not enough to produce a resonant peak.To search for low-energy resonant structures in isospin T=3/2 three-body systems, we have performed the experiments ^{3}H(t,^{3}He)3n and ^{3}He(^{3}He,t)3p at intermediate energies. For the 3n experiment, we have newly developed a thick Ti-^{3}H target that has the largest tritium thickness among targets of this type ever made. The 3n experiment for the first time covered the momentum-transfer region as low as 15 MeV/c, which provides ideal conditions for producing fragile systems. However, in the excitation-energy spectra we obtained, we did not observe any distinct peak structures. This is in sharp contrast to tetraneutron spectra. The distributions of the 3n and 3p spectra are found to be similar, except for the displacement in energy due to Coulomb repulsion. Comparisons with theoretical calculations suggest that three-body correlations exist in the 3n and 3p systems, although not enough to produce a resonant peak.
Polycrystalline Fe/Au superlattices were prepared by monatomic layer control on quartz glass substrates with MgO underlayers having a (0
0
1) texture, and their structural and magnetic properties ...have been compared with those for monocrystalline samples grown on MgO(0
0
1) single-crystal substrates. X-ray analysis have shown that the interface roughness and/or the disorder of superlattice structure in polycrystalline samples are larger than those in monocrystalline samples. It has been found that the perpendicular magnetic anisotropy is very sensitive to the interface morphology, while the magnitude of the Fe moment and the magnetooptical Kerr spectra are not seriously influenced by the interface morphology.
Jugular bulb oxygen saturation (SjO2) was monitored during preoperative embolization procedures in a consecutive series of 15 patients with large supratentorial arteriovenous malformations (AVM's) in ...order to test the hypothesis that changes in the shunt flow ratio can be continuously evaluated from the SjO2. A fiberoptic catheter was placed at the dominant jugular bulb. The SjO2 measured using jugular blood withdrawn before embolization was significantly higher than the SjO2 measured at the end of the final embolization procedure (mean +/- standard deviation 84.1% +/- 12.7% vs. 74.2% +/- 10.9%, p < 0.0001), showing a positive correlation with the AVM volume (r = 0.66, p < 0.001). Continuous monitoring of SjO2 via the fiberoptic catheter revealed a progressive decrease in association with the embolization procedures. Microsurgical resection of the AVM was performed at 1 to 2 weeks after the final embolization. Cases in which postoperative hemispheric deformation was revealed on computerized tomography demonstrated a higher SjO2 at the end of embolization compared to that in the remaining cases (81.6% +/- 8.6% vs. 67.8% +/- 8.4%, p < 0.008). Hemispheric deformation was observed in all cases in which the SjO2 did not decline to a level below 90% following embolization. The risk of severe hyperemic complications appeared to be greatly diminished when the SjO2 fell to below 80%. Assuming that the oxygen saturation of the perfusion flow (SjpO2) ranges from 50% to 75%, the ratio of the shunt flow to total flow at an SjO2 of 90% was estimated to be 0.6 to 0.8 based on the following equation: shunt flow/(perfusion flow + shunt flow) = (SjO2 - SjpO2)/(arterial oxygen saturation - SjpO2). These results suggest that monitoring the SjO2 provides real-time information concerning the progress of embolization and helps to determine whether the embolization has progressed sufficiently to avoid postoperative hyperemic complications.
