Hydrogen peroxide-induced oxidative stress promotes expression of CXCL15/Lungkine mRNA in a MEK/ERK-dependent manner in fibroblast-like synoviocytes derived from mouse temporomandibular joint

OBJECTIVES

Temporomandibular joint osteoarthritis (TMJ-OA) is a multifactorial disease caused by inflammation and oxidative stress. It has been hypothesized that mechanical stress-induced injury of TMJ tissues induces the generation of reactive oxygen species (ROS), such as hydroxyl radical (OH∙), in the synovial fluid (SF). In general, the overproduction of ROS contributes to synovial inflammation and dysfunction of the subchondral bone in OA. However, the mechanism by which ROS-injured synoviocytes recruit inflammatory cells to TMJ-OA lesions remains unclear.

METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to evaluate the mRNA expression of chemoattractant molecules. The phosphorylation levels of intracellular signaling molecules were evaluated using western blot analysis.

RESULTS

Hydrogen peroxide (H₂O₂) treatment significantly promoted mRNA expression of neutrophil chemoattractant CXCL15/Lungkine in a dose-dependent manner (100-500 μM) in fibroblast-like synoviocytes (FLSs) derived from mouse TMJ. H₂O₂ (500 μM) significantly upregulated the phosphorylation of extracellular signal-regulated kinase (ERK)1 and ERK2 in FLSs. Intriguingly, the mitogen-activated protein (MAP)/ERK kinase (MEK) inhibitor U0126 (10 μM) nullified H₂O₂-induced increase in CXCL15/Lungkine mRNA expression. Additionally, H₂O₂ (500 μM) administration significantly upregulated OH∙ production in FLSs, as assessed by live-cell permeant fluorescent probe targeted against OH∙ under fluorescence microscopy. Furthermore, the ROS inhibitor N-acetyl-l-cysteine (5 mM) partially but significantly reversed H₂O₂-mediated phosphorylation of ERK1/2.

CONCLUSIONS

H₂O₂-induced oxidative stress promoted the expression of CXCL15/Lungkine mRNA in a MEK/ERK-dependent manner in mouse TMJ-derived FLSs, suggesting that FLSs recruit neutrophils to TMJ-OA lesions through the production of CXCL15/Lungkine and exacerbate the local inflammatory response.

3D digital analysis of magnetic force-driven orthodontic tooth movement

With the introduction of rare earth magnets like neodymium-iron-boron (NdFeB), it has become possible to produce small magnets with high forces, necessary for its usage in the field of dentistry, such as for orthodontic tooth movement. The ultimate goal of this project is to establish magnetic force-driven orthodontic treatment as a future treatment modality for comprehensive orthodontic treatment. In order to utilize magnets for orthodontic treatment, we must first understand the characteristics of tooth movement created by magnetic forces. In this study, we aimed to digitally assess the efficacy of magnetic attraction and repulsion forces by means of a 3D digital analysis of movement (distance, direction, angulation and duration) and rotation (yaw, pitch and roll) of the crown and root of teeth in an ex vivo typodont model. We performed space closure and space gain treatment of maxillary central incisors (n = 30) and analyzed the movement and rotation of the teeth and root apex with 3D digital analysis. The results of the typodont model indicated significant differences on amount, speed and rotation of tooth and root movement created by magnetic attraction and repulsion forces. We also mimicked a moderate crowding typodont case and successfully treated it with a combination of attraction and repulsion magnetic forces. The moderate crowding case utilized magnets and a titanium archwire to guide the planned tooth movements and prevent undesired or unexpected movement. Further ex vivo experiments and considerations for biosafety will be necessary to investigate magnet force-driven orthodontics as a future modality of orthodontic treatment.

<p>Cephalometric Measurements Of Non-Syndromic Oligodontia In Early Dental Age In A Japanese Population</p>

Purpose

Patients and methods

Results

Conclusion

Characterization of PAX9 variant P20L identified in a Japanese family with tooth agenesis

Transcription factors PAX9 and MSX1 play crucial roles in the development of permanent teeth at the bud stage, and their loss-of-function variants have been associated with congenital tooth agenesis. We sequenced the coding regions of the PAX9 and MSX1 genes from nine patients with non-syndromic tooth agenesis, and identified a missense mutation, P20L, of PAX9 in a single familial case involving three patients in two generations. Identical mutation was previously reported by other authors, but has not been characterized in detail. The mutation was located in a highly conserved N-terminal subdomain of the paired domain and co-segregated as a heterozygote with tooth agenesis. The patients showed defects primarily in the first and second molars, which is typical for cases attributable to PAX9 mutation. Luciferase reporter assay using the 2.3-kb promoter region of BMP4 and electrophoretic mobility shift assay using the CD19-2(A-ins) sequence revealed that P20L substitution eliminated most of the transactivation activity and specific DNA binding activity of PAX9 under the experimental conditions we employed, while some residual activity of the mutant was evident in the former assay. The hypomorphic nature of the variant may explain the relatively mild phenotype in this case, as compared with other PAX9 pathogenic variants such as R26W.

Hydrophobic polypyrroles synthesized by aqueous chemical oxidative polymerization and their use as light-responsive liquid marble stabilizers

Hydrophobic polypyrroles doped with perfluoroalkyl dopants can function as a liquid marble stabilizer with photothermal properties.

Monitoring phase behavior of sub- and supercritical CO2 confined in porous fractal silica with 85% porosity

Phase behavior of CO(2) confined in porous fractal silica with volume fraction of SiO(2) phi(s) = 0.15 was investigated using small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) techniques. The range of fluid densities (0 < (rho(CO(2)))(bulk) < 0.977 g/cm(3)) and temperatures (T = 22 degrees C, 35 and 60 degrees C) corresponded to gaseous, liquid, near critical and supercritical conditions of the bulk fluid. The results revealed formation of a dense adsorbed phase in small pores with sizes D < 40 A at all temperatures. At low pressure (P < 55 bar, (rho(CO(2)))(bulk) < 0.2 g/cm(3)) the average fluid density in pores may exceed the density of bulk fluid by a factor up to 6.5 at T = 22 degrees C. This "enrichment factor" gradually decreases with temperature, however significant fluid densification in small pores still exists at temperature T = 60 degrees C, i.e., far above the liquid-gas critical temperature of bulk CO(2) (T(C) = 31.1 degrees C). Larger pores are only partially filled with liquid-like adsorbed layer which coexists with unadsorbed fluid in the pore core. With increasing pressure, all pores become uniformly filled with the fluid, showing no measurable enrichment or depletion of the porous matrix with CO(2).

Marked differences in volume phase transitions between gel and single molecule in DNA

Volume phase transitions of a DNA gel and a single giant DNA chain caused by spermidine(3+) (SPD(3+)) were investigated. The change in volume for the single DNA (VV(0) approximately 10(-5)) was four orders of magnitude greater than that for the DNA gel ( approximately 10(-1)), while the critical SPD(3+) concentration for the gel (1.8 mM) was one order of magnitude greater than that of the single DNA (0.12-0.25 mM) at the same pH 6.86. We tried to describe mean-field theories with virial expansion, which is valid for the coil-globule transition of a single polymer chain, for the volume phase transitions to explain the reason why such marked differences appeared. Considering the degree of the ordering of Kuhn segments arising from the gel network structure together with the chain length of cross-linked polymer chains, the volume phase transitions were described and then the significant differences were reproduced quantitatively. We concluded that the network structure plays a significant role in the volume phase transition of the gel.

Menger sponge-like fractal body created by a novel template method

We have established experimental strategies on how to create a Menger sponge-like fractal body and how to control its fractal dimension. The essence was to utilize alkylketene dimer (AKD), which spontaneously forms super-water-repellent fractal surface. We prepared "fractal AKD particles" with fractal surface structure as templates of pores in fractal body. The fractal body was synthesized by filling the remained space between the packed template particles with a tetramethyl orthosilicate solution, solidifying it by the sol-gel process, and removing the template by calcinations. We have succeeded in systematically creating fractal bodies of silica with different cross-sectional fractal dimensions D(cs)=1.87, 1.84, and 1.80 using "fractal template particles" compressed under the ratio=1.0, 2.0, and 3.0, respectively. We also discussed the possibilities of their fractal geometries in comparison with mathematical models. We concluded that the created fractal bodies were close to a Menger sponge and its modified one. Our experimental strategy allows us to design fractality of porous materials.

Rhythmic Conformational Change in a SinglePolymer Chain Induced by Laser Irradiation

We have investigated a rhythmic conformational change in a single polymer chain (T4DNA, 166 kbp, the contour length = 56 μm) between a folded state and a elongated state under thermodynamically open conditions using a focused continuons wave (cw) Nd:YAG laser beam (wavelength λ = 1064 nm), where the focused laser beam plays dual roles both of trapping of a polymer chain at the focus and making temperature gradient there. The oscillatory phenomenon is discuseed in terms of a limit-cycle oscillation with dissipation of photon energy.

Self-oscillating polymer chain in a laser field

We have investigated the dynamical behaviour of the rhythmic conformational change between the folded compact state and the unfolded state in a single polymer chain under thermodynamically open conditions. It is shown that the spontaneous rhythmic change in the conformation of a single polymer chain (T4DNA, 166 kbp, contour length: 56 microns) is generated using a focused continuous wave (CW) Nd:YAG laser beam (wavelength lambda = 1064 nm), where the focused laser beam plays a dual role, both trapping a polymer chain at the focus and creating a temperature gradient around the focus. Furthermore, the whole process of the rhythmic conformational change: the course of melting, nucleation and growth between the folded and unfolded states has been clarified. The rhythmic change in the conformation is discussed in terms of the limit-cycle oscillation driven by the dissipation of the photon energy.

Highly virulent strains of herpes simplex virus fail to kill mice following infection via gingival route

Virulence of herpes simplex virus (HSV) in mice has been demonstrated to be dependent on the site of infection. In this experiment, pathogenesis of HSV was studied in 2 different routes of infection in a mouse model system. When BALB/c mice were infected with 5 x 10(3) plaque-forming units (PFU) of virulent HSV type 1 Miyama GC+ strain (HSV-1-GC+) intraperitoneally, all mice were dead in 6 to 9 days. HSV-1-GC+ was recovered from organs such as the cerebrum, cerebellum, brainstem, and spleen 2 to 5 days after infection, but not from other organs such as trigeminal ganglia. However, if mice were infected in the maxillary gingiva with 1.0 x 10(7) PFU of HSV-1-GC+, all mice survived. HSV-1-GC+ was recovered from the trigeminal ganglia and brainstem 2 to 5 days after infection, but not from other organs tested. When mice were infected in maxillary gingiva with HSV-1-GC+, followed by the intraperitoneal injection of 6 mg of cyclophosphamide 72 hrs after virus infection, all mice were dead within days. Immunofluorescent and hematoxylin-eosin staining of gingival tissue sections revealed that when mice were infected in maxillary gingiva with HSV-1-GC+, 3 times as many gamma delta T-cells and 5 times as many polymorphonuclear cells can be detected in sections of maxillary gingiva when compared with non-infected mice. These data show that the gingiva of mice is considerably more resistant to infection with HSV, compared with the peritoneal cavity, and suggest the possible presence of an oral defense mechanism which might be different from that in the peritoneal cavity.

Demonstration of borna disease virus RNA in peripheral blood mononuclear cells derived from domestic cats in Japan

Borna disease virus (BDV) naturally infects horses, sheep, and several other species, including humans, and it is believed to be related to neurological disorders. BDV infection in domestic cats has also been demonstrated by serological assays. We demonstrated for the first time BDV RNA in peripheral blood mononuclear cells from 11 of 83 (13.3%) randomly selected domestic cats in Japan by nested reverse transcriptase-PCR. The BDVs from cats were similar to but slightly different from those from horses and humans, as shown by sequencing the reverse transcriptase-PCR products. None of the cats was positive for both BDV RNA and anti-BDV antibodies.

Exocrine pancreatic function in diabetic children

Exocrine pancreatic function was evaluated in 19 diabetic children on the basis of a pancreozymin-secretin test, a p-aminobenzoic acid (PABA) test, and a determination of fasting plasma trypsin and elastase-1 levels. In the pancreozymin-secretin test, the diabetics exhibited lower mean values in all the parameters measured, significant differences being seen in the volume of duodenal fluid and the output of bicarbonate and amylase. Compared to the controls, the diabetics also had lower levels in the PABA test and in the trypsin and elastase-1 measurements. No significant correlation was seen between exocrine pancreatic dysfunction and the duration of diabetes. However, the duration of diabetes in children who showed extremely low levels (below the mean +/- 2 SD for the control subjects) in the PABA test and low plasma trypsin and elastase-1 values was more than 1 year. This study revealed that diabetic children had reduced exocrine pancreatic function, some in an early stage of the disease. Therefore, the reduction may be due to a functional disturbance rather than to an anatomical loss of exocrine pancreatic tissue.

Conservative management of infantile pyloric stenosis by nasoduodenal feeding

Fifty cases of infantile plyoric stenosis were treated conservatively by transpyloric nasoduodenal tube feeding. The mean age on admission was 38.2 days. Transpyloric intubation was carried out in all patients and 45 (90%) with infantile pyloric stenosis were cured by nasuduodenal feeding. Among 5 (10%) requiring surgical intervention, abandonment of nasoduodenal feeding was the cause in only 3, and the parents chose an operation in the remaining 2 a few days after nasoduodenal feeding had been started. In non-surgically cured cases (45), mean body weights on admission and at discharge were 3,750 g and 5,177 g respectively; the duration of nasoduodenal feeding was 8 to 37 days (mean 17.2 days), mean weight gain during nasoduodenal feeding was 42.7 g/day and mean hospital stay was 39.7 days (38.0 days in 43 cases without any associated disorder). This experience suggests that nasoduodenal feeding in this report is a more effective treatment for infantile pyloric stenosis than any traditional medical treatment and it could be the preferred management in the small group of patients for whom an operation could carry a high risk, or whose parents refuse operation.