Photobiomodulation Activates Microglia/Astrocytes and Relieves Neuropathic Pain in Inferior Alveolar Nerve Injury.

Objective: This study aimed to determine microglial/astrocyte changes and their associated analgesic effect in inferior alveolar nerve injury (IANI) model rats treated with photobiomodulation therapy (PBMT) using a 940-nm diode laser. Background: Very few basic studies have investigated microglial/astrocyte dynamics following PBMT aimed at relieving neuropathic pain caused by IANI. Methods: Rats were divided into an IANI-PBM group, IANI+PBM group, and sham+PBM group. Observations were made on the day before IANI or the sham operation and on postoperative days 3, 5, 7, 14, and 28. PBMT was delivered for 7 consecutive days, with an energy density of 8 J/cm2. Behavioral analysis was performed to determine pain thresholds, and immunohistological staining was performed for the microglia marker Iba1 and astrocyte marker glial fibrillary acidic protein, which are observed in the spinal trigeminal nucleus. Results: Behavioral analysis showed that the pain threshold returned to the preoperative level on postoperative day 14 in the IANI+PBM group, but decreased starting from postoperative day 1 and did not improve thereafter in the IANI-PBM group (p ≤ 0.001). Immunological analysis showed that microglial and astrocyte cell counts were similar in the IANI+PBM group and IANI-PBM group shortly after IANI (day 3), but the expression area was larger (p ≤ 0.001) and hypertrophy of microglia and astrocyte cell bodies and end-feet extension (i.e., indicators of activation) were more prominent in the IANI+PBM group. Conclusions: PBMT after IANI prevented hyperalgesia and allodynia by promoting glial cell activation shortly after injury.

CO2 Laser for Esthetic Healing of Injuries and Surgical Wounds with Small Parenchymal Defects in Oral Soft Tissues.

A number of studies have recently demonstrated the effectiveness of CO2 laser irradiation for the repair and regeneration of scar tissue from injuries or surgical wounds. However, such studies of the oral mucosa are highly limited. Previous studies using CO2 laser irradiation have indicated that two factors contribute to esthetic healing, namely, artificial scabs, which are a coagulated and carbonized blood layer formed on the wound surface, and photobiomodulation therapy (PBMT) for suppressing wound scarring and promoting wound healing. This review outlines basic research and clinical studies of esthetic healing with the use of a CO2 laser for both artificial scab formation by high-intensity laser therapy and PBMT in the treatment of injuries and surgical wounds with small parenchymal defects in oral soft tissues. The results showed that the wound surface was covered by an artificial scab, enabling the accumulation of blood and the perfusion necessary for tissue regeneration and repair. Subsequent PBMT also downregulated the expression of transformation growth factor-b1, which is involved in tissue scarring, and decreased the appearance of myofibroblasts. Taken together, artificial scabs and PBMT using CO2 lasers contribute to the suppression of scarring in the tissue repair process, leading to favorable esthetic and functional outcomes of wound healing.

Space-making effect for new bone formation by suppressing scar contraction of mucosal epithelium of rat tooth extraction wound using diode laser and CO2 laser treatment.

Background/purpose: As an extraction wound closes, the mucosal epithelium of the tooth extraction wound impedes the space for new bone formation by invading into the extraction socket. Thus, the height of the alveolar crest decreases, causing significant depression of the alveolar mucosa. In this study, we created a rat tooth extraction model and examined the effects of laser irradiation by CO2 and diode on the dynamics of myofibroblast expression through α-SMA, and TGF-ß1. Materials and methods: After tooth extraction of five-week-old male Wistar rats, they were divided into two laser treatment groups (CO2 laser or diode laser was irradiated into tooth extraction socket) and non-laser treatment group (control group). Surrounding tissues, including the extraction socket, were removed at 3, 5, 7, and 21 days after tooth extraction and the expression of α-SMA and TGF-ß1 was verified using immunohistological techniques (6 animals in each group and each period, 72 animals in total). Results: α-SMA-positive cells and TGF-ß1-positive areas were significantly lower in the two laser treatment groups than in the control group. Particularly, the diode group almost had no TGF-ß1-positive areas on the 21st day when healing after tooth extraction was deemed to be completed. Conclusion: Both CO2 and diode laser irradiation of tooth extraction wounds decreases α-SMA-positive cells and TGF-ß1-positive areas. Further, it causes a decrease in myofibroblast expression and suppresses the invasion of mucosal epithelium into the extraction socket. Therefore, laser irradiation may exert a space-making effect for new bone formation and also contribute to socket preservation.

A narrative review and clinical anatomy of herpes zoster infection following COVID-19 vaccination.

INTRODUCTION: In this review, cases of herpes zoster (HZ) infection following receipt of COVID-19 vaccines will be analyzed. We also present two cases of oral HZ following the COVID-19 vaccine and discuss this clinical anatomy. MATERIALS AND METHODS: A database search using PubMed was conducted in August 2021 and 20 articles were found to be eligible for review. Patient data and vaccine information were analyzed. In addition, two cases of oral HZ infection following the receipt of COVID-19 vaccines are presented. RESULTS: A total of 399 cases were identified. The affected dermatomes mimicked the regular distribution of HZ. For the dermatomes of the face, the various reports used different ways to describe the areas involved; CNV, CNV1, CNV2, CNV3, lower jaw, forehead, and under the eyebrow (CNV, 2 cases; CNV1, 4 cases; CNV2, 3 cases; and CNV3, 3 cases). Some patients who had a history of varicella zoster virus vaccination had HZ following the COVID-19 vaccination. Two patients with oral HZ following vaccination were found to have involvement of the greater palatine nerve. CONCLUSIONS: Vaccine-related HZ cases have been reported worldwide. Although many studies with a larger number of cases are ongoing, detailed information can be obtained from case reviews as reported herein.

Oral Herpes Zoster Infection Following COVID-19 Vaccination: A Report of Five Cases.

Recently, two cases of oral herpes zoster (HZ) following COVID-19 vaccines were reported. It was suggested that COVID-19 vaccine-related oral HZ cases might be missed or misdiagnosed as stomatitis or isolated oral herpes. In this report, five cases of oral HZ following COVID-19 vaccinations are presented. Four cases were observed on the hard palate (V2), and one case was found on the mandible (V3). Four patients did not receive any treatment for their oral HZ, but one patient also had skin reactions on her right orbit and ear and was thus treated with an antiviral drug. As these cases were seen during such a short period of time and in one practice, the relationship with the COVID-19 vaccination appears to be related.

Healing of Open Upper Lip Vermillion Wounds Irradiated with CO2 Laser Immediately After Injury.

Objective: To evaluate the healing of open upper lip vermillion wounds irradiated with CO2 laser immediately after injury. Background: There are reports of using CO2 laser therapy on healed wounds for scar tissue reduction. However, limited data exist regarding its use immediately after an injury. Thus, the role of CO2 laser in wound healing remains unclear. Methods: Two patients with open upper lip vermillion wounds were treated using CO2 laser irradiation to the area postsuturing. Results: Good functional and aesthetic results were obtained from the therapy, with no postoperative pain complaints or infection. Conclusions: CO2 laser irradiation, performed immediately after an injury, could be an effective treatment option for open vermillion wounds.

Wound Healing and Cell Dynamics Including Mesenchymal and Dental Pulp Stem Cells Induced by Photobiomodulation Therapy: An Example of Socket-Preserving Effects after Tooth Extraction in Rats and a Literature Review.

High-intensity laser therapy (HILT) and photobiomodulation therapy (PBMT) are two types of laser treatment. According to recent clinical reports, PBMT promotes wound healing after trauma or surgery. In addition, basic research has revealed that cell differentiation, proliferation, and activity and subsequent tissue activation and wound healing can be promoted. However, many points remain unclear regarding the mechanisms for wound healing induced by PBMT. Therefore, in this review, we present an example from our study of HILT and PBMT irradiation of tooth extraction wounds using two types of lasers with different characteristics (diode laser and carbon dioxide laser). Then, the effects of PBMT on the wound healing of bone tissues are reviewed from histological, biochemical, and cytological perspectives on the basis of our own study of the extraction socket as well as studies by other researchers. Furthermore, we consider the feasibility of treatment in which PBMT irradiation is applied to stem cells including dental pulp stem cells, the theme of this Special Issue, and we discuss research that has been reported on its effect.

High-Pressure Synthesis and Crystal Structure of the Sulfur-Richest Chromium Sulfide CrS3 Composed of Cr(III) and Disulfide Ions.

The new binary chromium sulfide CrS3 has been synthesized by reaction of Cr3S4 and sulfur mixtures at 800 °C and 13 GPa. CrS3 crystallizes in an orthorhombic unit cell with a = 4.6742(7) Å, b = 5.7315(8) Å, c = 10.603(2) Å, and V = 284.873(4) Å3. It has a novel structure composed of Cr2S10 edge-shared octahedral dimers, which share all of their corners to form a three-dimensional structure. All of the sulfur atoms form S22- disulfide ions with a S-S distance of 2.063(5) or 2.068(8) Å. The structure of CrS3 is a derivative of the crystal structure of marcasite FeS2, in which one in three metal sites of the marcasite structure is vacant in the CrS3 structure.

Utility of High-Intensity Laser Therapy Combined with Photobiomodulation Therapy for Socket Preservation After Tooth Extraction.

Objective: High-intensity laser therapy (HILT) combined with photobiomodulation therapy (PBMT) using a diode or CO2 laser was administered after extraction of the left first molar in rats. Effects on socket preservation (preservation of the alveolar bone and healing time after extraction) were evaluated histopathologically. Background: Irradiation using a diode or CO2 laser has been shown to hasten wound healing, but the effects remain controversial. Methods: Five-week-old male Wistar rats that underwent extraction of the left maxillary first molar were divided into three groups: diode laser irradiation (diode group), CO2 laser irradiation (CO2 group), and no laser irradiation (control group). HILT (27 J) was performed immediately after tooth extraction to enhance blood coagulation, followed by PBMT (0.7 J) 1 day later to enhance healing. Tissues, including the extraction socket, were removed en bloc 3, 5, 7, 10, and 21 days postextraction to determine the morphological characteristics of wound healing and the distribution of myofibroblasts involved in scar formation. Results: In the diode and CO2 groups, new bone formation and cancellous bone maturation were observed at an early stage of wound healing. The number of myofibroblasts was significantly lower in the laser treatment groups than the control (p < 0.001), and both treatment groups had a significantly higher alveolar crest height (p < 0.01), with almost no concavity in the mucosa of the extraction wound. Conclusions: Combined HILT and PBMT following tooth extraction hastened wound healing and preserved alveolar crest height, suggesting a role in socket preservation.

NHC-catalyzed cleavage of vicinal diketones and triketones followed by insertion of enones and ynones.

Thiazolium carbene-catalyzed reactions of 1,2-diketones and 1,2,3-triketones with enones and ynones have been investigated. The diketones gave α,ß-double acylation products via unique Breslow intermediates isolable as acid salts, whereas the triketones formed stable adducts with the NHC instead of the coupling products.

High-Pressure Synthesis and Electronic Structure of a New Superconducting Strontium Germanide (SrGe3) Containing Ge2 Dumbbells.

We obtained a new strontium germanide (SrGe3) by high-pressure and high-temperature synthesis. It was prepared at 13 GPa and 1100 °C. The space group and cell constants are I4/mmm (No. 139), a = 7.7800(8) Å, c = 12.0561(13) Å, and V = 729.74(17) Å(3). SrGe3 crystallizes in the CaSi3 structure composed of Ge-Ge dumbbells and Sr(2+) ions. SrGe3 is a type II superconductor with a transition temperature of 6.0 K.

New polymorph of Mo3S4 prepared using a high-pressure synthesis technique: crystal structure, electronic property, and band calculation.

A new polymorph of Mo3S4 was synthesized at 13 GPa and 1450 °C from a stoichiometric mixture of elements. It crystallizes in a triclinic unit cell (space group P1 (No. 2)) with cell constants of a = 6.364(2) Ǻ, b = 6.608(2) Ǻ, c = 6.809(2) Ǻ, α = 103.899(3) °, ß = 117.753(3) °, γ = 103.958(3) °, and V = 224.25(13) Ǻ(3). The structure of Mo3S4 is composed of edge- and face-sharing MoS6 octahedra. It was closely related to the structure of MMo2S4 type compounds (M = V, Cr, Fe, and Co). Mo3S4 can be regarded as a derivative with M = Mo. The calculated density of 6.160 g/cm(3) was much larger than 5.191 g/cm(3) of famous polymorphic Mo6S8 (Chevrel phase). Mo3S4 was metallic and did not show any superconducting transition down to 2 K. The bond-valence sums suggested that Mo3S4 can be classified in the class III-B of mixed-valence compounds; all Mo ions have a similar nonintegral valence. Electronic structure calculations revealed that the conduction band of Mo3S4 contains much contribution of the relatively narrow Mo 4d bands as well as the bands composed of hybridized Mo4d-S3d orbitals.

High-pressure synthesis and superconductivity of a new binary barium germanide BaGe3.

A new binary barium germanide BaGe(3) was prepared by high-pressure and high-temperature reactions using a Kawai type multi-anvil press. It crystallizes in a hexagonal unit cell with a = 6.814(1) Å, c = 5.027(8) Å, and V = 202.2(5) Å(3) (the space group P6(3)/mmc, No. 194). The unit cell contains two layers along the c axis composed of Ba atoms and Ge(3) triangular units. The triangular units stack along the c axis to form 1D columns in which the adjacent Ge(3) units turn to opposite directions. The columns, therefore, can be described as the face-sharing stacking of elongated Ge(6) octahedra. Each Ba atom is surrounded by six columns. BaGe(3) is metallic and shows superconductivity at 4.0 K. The band structure calculations revealed that there are four conduction bands mainly composed of Ge 4p and Ba 5d orbitals. From Fermi surface analysis, we confirmed that three of them have a large contribution of Ge 4pz orbitals in the vicinity of the Fermi level and show a simple 1D appearance. The remaining one contains Ge 4px, 4py, and Ba 5d contributions and shows a 2D property.

High-pressure synthesis and superconductivity of a new binary lanthanum germanide LaGe3 with triangular Ge3 cluster units.

We prepared a new binary lanthanum germanide, LaGe(3), under high-pressure and high-temperature conditions (3-12 GPa, 500-1200 °C). It crystallizes in the BaPb(3) structure (the space group R ̅3m) with lattice constants of a = 6.376(1) Å, c = 22.272(3) Å, and V = 784.1(2) Å(3). We refined the structure using Rietveld analysis from X-ray powder data. The structure is composed of two types of close-packed atom layers. In one layer, every La atom is surrounded solely by Ge atoms with the same distance of 3.188 Å. The other layer contains Ge(3) regular, triangular cluster units with a Ge-Ge distance of 2.634 Å. The electron localization function and crystal orbital Hamilton population calculations suggest that the triangular cluster is composed of three Ge-Ge covalent bonds and that each Ge atom has a lone pair. The temperature dependence of the magnetic susceptibility and electrical conductivity measurements revealed that LaGe(3) is metallic and shows superconductivity at 7.4 K. This critical temperature is highest for the La-Ge system.

Influence of carbon dioxide laser irradiation on the healing process of extraction sockets.

OBJECTIVE: To clarify the healing-promoting effects of carbon dioxide laser irradiation in high and low reactive-level laser therapies (HLLT and LLLT, respectively) on extraction sockets after tooth extraction. MATERIAL AND METHODS: Forty-two 5-week-old male Wistar rats were divided into laser irradiation and non-irradiation (control) groups and compared. The laser-irradiation group underwent HLLT immediately after tooth extraction and then LLLT 1 day post-extraction. Tissue was excised 6 h and 3, 7, or 21 days after extraction and histopathologically investigated. The alveolar crest height was measured osteomorphometrically 21 days post-extraction, and granulation tissue in the extraction socket surface layer was immunohistologically investigated using anti-α-smooth muscle actin (anti-α-SMA) antibody 3 and 7 days post-extraction. RESULTS: Many osteoclasts appeared and active bone resorption was noted in the irradiation group 3 days after extraction compared to the controls. On Day 7, new bone formation started around the extraction socket in the control group, but from the superficial to over the middle layer of the socket in the irradiation group. On Day 21, a concavity existed in the alveolar crest region in the controls, whereas this region was flat, with no concavity, in the irradiation group. On osteomorphometry, the alveolar crest height was significantly higher in the irradiation (0.7791 ± 0.0122) than the control (0.6516 ± 0.0181) group (P < 0.05). On immunostaining, many α-SMA-positive cells were noted in the control group, but very few in the irradiation group. CONCLUSION: Laser-irradiated extraction wound healing showed characteristics different from those of the normal healing process, suggesting a favorable healing-promoting effect.

Electron-phonon interactions of Si100 and Ge100 superconductors with Ba atoms inside.

The absolute density of states of isostructural Ba24Si100 and Ba24Ge100 near the Fermi level, which is very relevant for discussion on phonon-mediated superconductivity, is quantitatively evaluated to be 0.28 states eV⁻¹/Ge atom and 0.18 states eV⁻¹/Si   atom by combining soft x-ray photoelectron spectroscopy and magnetic susceptibility measurements. The energetics of the anharmonic motions of the endohedral Ba atoms are also discussed on the basis of the 4d-core-level spectra. The discussion based on these important physical parameters concludes that the unique electron-phonon interactions do not occur due to the local Jahn-Teller distortion of the fragile open cage structure in the phonon-mediated BCS formalism. Compounds with a rigid cage would be essential to give rise to anticipated unique interactions as a key ingredient favored for superconducting paring.

Reversible emergence of a self-assembled layered structure from three-dimensional isotropic ionic crystal of a cluster compound (4-HNC5H4OH)2Mo6Cl14 driven by absorption of water and alcohols.

The compound comprising nanometer scale cluster molecules showed unusual reversible structural transformation between an isotropic ionic crystal and a layered structure of which the interlayer spaces are filled with the absorbed molecules.

[Five-year results of prostate specific antigen (PSA) screening in Yokosuka City--comparative study between PSA-screened group and non-screened group].

A mass screening of subjects for prostate specific antigen (PSA) was conducted to investigate whether this method is effective in detection of early stage prostate cancer. From 2001 to 2005, 1022 patients in Yokosuka City with pathologically diagnosed prostate cancer by using prostate needle biopsy were divided into screened (S: 276 patients) and non-screened (NS: 746 patients) groups. Clinical factors (mean age, PSA at diagnosis, clinical stage, Gleason score, WHO classification, cases of radical prostatectomy) were evaluated and analyzed. Statistical significance was analyzed by Mann-Whitney's U-test. The mean age was 70.7 and 72.7 (p<0.0001) in the S group and NS group, respectively; mean PSA at diagnosis was 10.5 and 18.6 ng/ml (P=0.0139); percentage of organ-confined disease (T2b or lower clinical stage), 75 and 55 (p<0.0001); percentage of non-metastatic diseases was 92 and 77 (p<0.001) and percentage of pathologically poor-risk cancer (8 or more Gleason score) was 22 and 38 (p=0.0004), respectively. In conclusion, PSA mass screening was found useful to detect early stage prostate cancer in Yokosuka City. Further studies should be conducted to determine whether PSA mass screening will be able to decrease mortality of prostate cancer.

Formation of wormlike aggregates of fluorocarbon-hydrocarbon hybrid surfactant by Langmuir-Blodgett transfer and alignment of gold nanoparticles.

A novel anionic fluorocarbon-hydrocarbon hybrid surfactant (SS-Hyb-Na+) with a disulfide group has been synthesized from 11-bromo-1-undecanal and perfluorohexylethyl iodide via three steps. The Langmuir-Blodgett (LB) transfer of the 1:100 (mol/mol) mixed monolayer of SS-Hyb-Na+ and stearyl alcohol (C18OH) formed on an aqueous solution containing a cationic polymer, poly(diallyldimethylammonium chloride) (PDDA+Cl-) onto a hydrophobic silicon wafer yields the formation of wormlike aggregates consisting of SS-Hyb-/PDDA+ polyion complexes. It is found that the aggregates align along the withdrawal direction of the wafer substrate. When the wafer on which the wormlike aggregates exist is immersed into the dispersion of gold nanoparticles (Au NPs) prepared by the citrate reduction method, Au NPs align along the wormlike structures. Even though the surface of the wafer is placed either vertical or parallel to the monolayer compression direction during the LB transfer, the one-dimensional (1D) array of Au NPs is observed along the withdrawal direction of the wafer. This indicates that the wormlike aggregates of SS-Hyb-/PDDA+ complexes are aligned during the LB transfer, and the aligned aggregates behave as a scaffold in the 1D array of Au NPs.