COVID-19 transmission in dental and oral/maxillofacial surgical practice during pandemic: questionnaire survey in 51 university hospitals in Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a major public health problem. Dental procedures that generate aerosols are considered to impose a high risk of infection; therefore, dental professionals, such as dentists and dental hygienists, may be at high risk of viral transmission. However, few studies have reported COVID-19 clusters in dental care settings. AIM: To investigate whether dental and oral/maxillofacial procedures are associated with the occurrence of COVID-19 clusters and measures taken to prevent nosocomial infection in dental clinics. METHODS: An online questionnaire survey on clinical activities (administrative control), infection control measures (environmental/engineering control, personal protective equipment, etc.), and confirmed or probable COVID-19 cases among patients and clinical staff was administered to the faculties of the dental and oral/maxillofacial surgical departments of university hospitals. FINDINGS: Fifty-one faculty members completed the questionnaire. All members were engaged in the treatment of dental and oral surgical outpatients and actively implemented standard precautions. Fourteen faculty members treated patients with COVID-19, but no infections transmitted from the patients to the medical staff were observed. In seven facilities, patients were found to have the infection after treatment (medical staff came in close contact), but there was no transmission from patients to medical staff. Four facilities had medical staff with infections, but none of them exhibited disease transmission from staff to patients. CONCLUSION: COVID-19 clusters are unlikely to occur in dental and oral surgical care settings if appropriate protective measures are implemented.

Evaluation of Papillomacular Nerve Fiber Bundle Thickness in Glaucoma Patients with Visual Acuity Disturbance.

PURPOSE: Assessing the papillomacular nerve fiber bundle (PMB) can identify glaucoma patients with decreased visual acuity. In this study, we explore efficient methods for evaluating PMB thickness in glaucoma patients, based on swept source-optical coherence tomography (SS-OCT). METHODS: This study included 347 eyes of 205 open-angle glaucoma (OAG) patients. Patients were excluded if they had best-corrected decimal visual acuity < 0.3, axial length >28 mm, non-glaucoma ocular disease, or systemic disease affecting the visual field. We obtained vertical 12.0 × 9.0 mm 3D volume scans covering both the macular and optic disc regions with SS-OCT (DRI OCT Triton, Topcon), and measured the thickness of the PMB, as well as average macular retinal nerve fiber layer thickness (mRNFLT) and macular ganglion cell complex thickness (mGCCT) in the macular map and temporal-quadrant circumpapillary RNFL thickness (tcpRNFLT). We also measured central-strip RNFLT (csRNFLT) and GCC (csGCCT) in a 1.5 × 6.6 mm area of the scan centered between the fovea and optic nerve head. CsRNFLT and csGCCT were divided lengthwise into three 1.5 × 2.2 mm sections. We then calculated Spearman's rank correlation coefficient between these OCT measurements and visual acuity. Logistic regression analysis was used to find the cutoff value for the OCT measurements to predict logMAR < 0. RESULTS: The correlation coefficients with logMAR were 0.38 for mRNFLT, 0.44 for mGCCT, 0.37 for middle csRNFLT, 0.50 for middle csGCCT, and 0.33 for tcpRNFLT (all P < .0001). For middle csGCCT, the area under the curve indicating decreased visual acuity was 0.80, with a cutoff value of 88.6 µm (P < .001). CONCLUSIONS: We found strong associations between OCT parameters in the PMB, especially middle csGCCT, and visual acuity in patients with OAG. The thickness of the PMB may therefore be valuable information for glaucoma care and may help prevent visual acuity disturbance.

Very-low-voltage operation of Mach-Zehnder interferometer-type electroabsorption modulator using asymmetric couplers.

We have proposed and developed a new type of electroabsorption modulator (EAM) that employs both optical absorption and interferometric extinction. The EAM operates at a record low voltage of 0.2 V at 25.8-Gbit/s modulation, which can reduce optical transmitter power consumption and allows the adoption of cost-effective CMOS drivers.

Toxicity and outcomes after chemoradiation for esophageal cancer in patients age 75 or older.

Randomized trials of chemoradiation for esophageal cancer have included very few patients age > or = 75. In this retrospective study, we describe the outcomes and toxicity of full-dose chemoradiation in elderly patients with esophageal cancer. Patients, age > or = 75, treated with full-dose chemoradiation for esophageal carcinoma from 2002 to 2008 were retrospectively reviewed. Thirty-four patients were identified with a median age of 79.5 (range 75-89). The median Eastern Cooperative Oncology Group performance status was 1 (range 0-3) and the median Adult Comorbidity Evaluation-27 score was 1 (range 0-3). Twenty-eight patients received definitive and six received neoadjuvant chemoradiation. The median radiation dose delivered was 50.4 Gray (range 3.6-68.4 Gray). Platinum-based chemotherapy was used in 79.4% of patients. Fifty percent of the patients completed all planned radiation therapy (RT) and chemotherapy; 85.3% completed RT. Acute toxicity > or = grade 4 occurred in 38.2% of patients, and 70.6% of the patients required hospitalization, emergency department visit, and/or RT break. Median follow-up was 14.5 months among 7 survivors, and median survival was 12.0 months (95% confidence interval [CI]: 9.7 to 24.1 months). The actuarial overall survival at 2 years was 29.7% (95% CI: 16.6 to 52.6%). There were four treatment-related deaths. The median time to any recurrence was 10.4 months. Nineteen patients had a local and/or distant recurrence. In conclusion, elderly patients experienced substantial morbidity from chemoradiation, and long-term survival was low. Future efforts to improve treatment tolerability in the elderly are needed.

Metallicity and positive magnetoresistance induced by Pb substitution in a misfit cobaltate crystal.

We have synthesized single crystals of the misfit-layered cobalt oxide, [Bi(1.5)Pb(0.5)Sr(2)O(4-δ)][CoO(2)](1.86), with quadruple NaCl-type layers, using a flux method, and measured their transport properties. From structural refinements, it is found that the modulation in the BiO layer observed in [Bi(1.74)Sr(2)O(4-δ)](RS)[CoO(2)](1.82) is suppressed by Pb substitution. The in-plane resistivity, thermopower, and Hall coefficient are 4.3  mΩ cm, 101  µV K(-1), and 1 × 10(-2) cm(3) C(-1) at 300 K, respectively; these are consistent with those of the misfit-layered cobalt oxides. All of these values are smaller than those of [Bi(1.74)Sr(2)O(4)][CoO(2)](1.82), indicating that the carrier concentration is larger than that of the undoped crystal. Moreover, the low T upturn of resistivity observed for most of the cobalt misfit oxides is replaced by a metallic behavior, following a T(2) dependence, indicating strong correlations in the Pb-doped crystal. Also, the magnetoresistance, usually negative for misfit oxides, is replaced by a small positive magnetoresistance. Doping with Pb is thus an efficient way to suppress the low T localized behavior usually observed for misfits.

Transition-metal oxides with triangular lattices: generation of new magnetic and electronic properties.

The search for multifunctional materials as multiferroics to be applied in microelectronic or for new, chemically stable and nontoxic, thermoelectric materials to recover waste heat is showing a common interest in the oxides whose structures contain a triangular network of transition-metal cations. To illustrate this point, two ternary systems, Ba-Co-O and Ca-Co-O, have been chosen. It is shown that new phases with a complex triangular structure can be discovered, for instance, by introduction of Ga (3+) into the Ba-Co-O system to stabilize Ba 6Ga 2Co 11O 26 and Ba 2GaCo 8O 14, which both belong to a large family of compounds with formula [Ba(Co,Ga)O 3-delta] n [BaCo 8O 11]. In the latter, both sublattices contain triangular networks derived from the hexagonal perovskite and the spinel structure. Among the hexagonal perovskite, the Ca 3Co 2O 6 crystals give clear evidence where the coupling of charges and spins is at the origin of a magnetocapacitance effect. In particular, the ferrimagnetic to ferromagnetic transition, with a one-third plateau on the M( H) curve characteristic of triangular magnetism, is accompanied by a peak in the dielectric constant. A second class of cobaltites is the focus of much interest. Their 2D structure, containing CoO 2 planes isostructural to a CdI 2 slice that are stacked in an incommensurate way with rock salt type layers, is referred to misfit cobaltite. The 2D triangular network of edge-shared CoO 6 octahedra is believed to be responsible for large values of the Seebeck coefficient and low electrical resistivity. A clear relationship between the structuresincommensurability ratiosand the electronic properties is evidenced, showing that the charge carrier concentration can be tuned via the control of the ionic radius of the cations in the separating layers.

Retinoic acid-inducible gene-I is induced in gingival fibroblasts by lipopolysaccharide or poly IC: possible roles in interleukin-1beta, -6 and -8 expression.

Retinoic acid-inducible gene-I (RIG-I) is a member of the DExH family of proteins, and little is known of its biological function in the oral region. We previously reported that interleukin 1beta (IL-1beta) induced RIG-I expression in gingival fibroblasts. In this study, we studied the mechanism of RIG-I expression induced by lipopolysaccharide (LPS) or double-stranded RNA (dsRNA) in gingival fibroblasts. We also addressed the role of RIG-I in the expression of IL-1beta, IL-6 and IL-8 in gingival fibroblasts stimulated with LPS or dsRNA. We stimulated cultured human gingival fibroblasts with LPS or dsRNA, and examined the expression of RIG-I mRNA and protein. The effect of cycloheximide, a protein synthesis inhibitor, on RIG-I induction by these stimuli was examined. The expression of IL-1beta, IL-6 and IL-8 in gingival fibroblasts transfected with RIG-I cDNA stimulated with LPS or dsRNA was examined. LPS or dsRNA induced the expression of mRNA and protein for RIG-I in concentration- and time-dependent manners. We also examined the localization of RIG-I, and found that it was expressed in cytoplasm. Cycloheximide did not suppress the LPS or dsRNA-induced RIG-I expression. Introduction of RIG-I cDNA into gingival fibroblasts resulted in enhanced expression of IL-1beta, IL-6 and IL-8; moreover, overexpression of RIG-I stimulated with LPS or dsRNA synergistically increased expression of IL-1beta, IL-6 and IL-8. RIG-I may have important roles in the innate immune response in the regulation of IL-1beta, IL-6 and IL-8 expression in gingival fibroblasts in response to LPS and dsRNA.

[The trend of the drug eruptions in the last fifteen years].

The drug eruptions are known to often become more severe by the readministration of causative drugs. It is an important theme to prevent the relapse of the drug eruptions. We have been monitoring drug adverse reactions at our hospital since October, 1980. We divided fifteen years from October, 1980 to September, 1995 into three periods; the first period (Oct., 1980-Sep. 1985), the second period (Oct., 1985-Sep., 1990), and the third period (Oct., 1990-Sep., 1995), and discussed the trend of the drug eruptions appeared among these three periods. The number of the drug eruptions increased. But the proportion to the total drug adverse reactions and to the number of patients slightly decreased. The eruptions in women much increased and in the patients of forties or older generations also increased. But in patients of thirties or younger generations decreased. While nonsteroidal anti-inflammatory drugs (NSAIDs) other than pyrines, antibiotics other than penicillins and cephalosporins and drugs affecting the cardiovascular system and the metabolism tend to increase, pyrines, penicillins, iodic and biliary contrast media tend to decrease. The incubation period before the eruption appeared is less than three days in most antibiotics and anti-inflammatory drugs. But it is more than four days in most drugs for chronic diseases. Other symptoms such as nausea, fever and liver dysfunction were shown in 9.2% of the drug eruptions. In 8.9% of the drug eruptions a relapse of allergic reactions included eruptions were also found. In some cases the drug eruptions exacerbate by re-administration of beta-lactam antibiotics. In the case of administration of drugs, it is necessary to pay attention to dermatitis caused by the drugs. And we recognized the importance of the system for the prevention of the relapse of drug eruptions including injections.

Free omental transfer for osteoradionecrosis of the mandible.

Osteoradionecrosis (ORN) of the mandible can arise following therapeutic radiotherapy for head and neck cancer. The incidence is quoted as 10-15%. Conservative and surgical therapies used for ORN have included vascularized osteocutaneous flap transfers, hyperbaric oxygen and ultrasound therapy. We have used an omental transfer for ORN without a segmental resection. We wrapped the affected mandible within the omentum in order to promote revascularization and neocellularity. Four patients suffering from ORN have undergone omental transfers. Two cases developed pathologic fractures postoperatively that were successfully treated by conservative management. In all cases, the patients' intractable pain improved, and no patient showed recurrence of ORN or wound dehiscence. Postoperative bone scintigrams showed the same degree of accumulation in the lesion as in normal adjacent bone. These results demonstrate the effectiveness of omental transfer and suggest that omental transfer has a promising place in the management of ORN.

Oligosaccharide esters from the roots of Polygala arillata.

Two new sucrose esters, arillatoses A (1) and B (2), and four new trisaccharide esters, arillatoses C-F (3-6), were isolated from the roots of Polygala arillata, together with four known sucrose esters, glomeratose E (7) and sibiricoses A(1) (8), A(5) (9), and A(6) (10). The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence.

Tetrasaccharide multi-esters and xanthone glycosides from the roots of Polygala wattersii.

Ten new tetrasaccharide multi-esters, watteroses A-J (1-10), and two new xanthone glycosides, wattersiixanthones A (11) and B (12), were isolated from the roots of Polygala wattersii, together with 11 known compounds (10 oligosaccharide multi-esters and a xanthone glycoside). The structures of new compounds were elucidated on the basis of chemical and spectroscopic evidence.

Lidocaine added to a tracheostomy tube cuff reduces tube discomfort.

PURPOSE: To examine whether lidocaine diffusion across an endotracheal tube cuff affects tracheostomy tube discomfort. METHODS: Two tracheostomy tube cuffs were inflated with 5 ml lidocaine 4% solution and air at 20 cmH2O, and then placed in 20 ml distilled water at 37 degrees C. After vigorous stirring, 100 microl of this water was then sampled immediately then 1, 2, 4, 8, 24 hr later to measure lidocaine concentration by high-performance liquid chromatography. Sixteen patients undergoing tracheostomy following oral cancer resection were randomly assigned to two groups: lidocaine (n=8) and placebo (n=8). A tracheostomy tube cuff was inflated with 5 ml lidocaine 4% or saline 0.9% and air to a cuff pressure of 20 cmH2O, in the lidocaine and placebo groups respectively. Tube discomfort was evaluated using a visual analogue scale at 0, 0.5, 1, 2 and 4 hr after lidocaine or saline administration. Neither analgesics nor sedatives was given during the evaluation period. RESULTS: Lidocaine time-dependently diffused across the tracheostomy tube cuff. Thirty and 60 min after cuff inflation lidocaine concentrations in the water bath reached approximately 8 and 17 microg x ml(-1) representing 160 and 340 microg in 20 ml of water, respectively. The VAS decreased from 53.5 +/- 10.6 to 25.1 +/- 9.8 mm (P < 0.01) 0.5 hr following lidocaine administration which continued until the end of evaluation period. In the placebo group, VAS did not change. CONCLUSION: Lidocaine diffusion across the tracheostomy tube cuff reduces tube discomfort.

Mycetoma.

Subcutaneous fungal infections are relatively uncommon in the lower extremity. Mycetoma begins as painless papules or nodules that increase in size and progresses to involve the connective tissue. Diagnosis is based on biopsy, with definitive identification of the organism needed for effective treatment. Treatment consists of antifungal medications and surgical debridement. This article provides an overview of this disorder and reports on a case of recurrent mycetoma in a 70-year-old woman.

Expression of tumor necrosis factor-alpha and interleukin-6 in oral squamous cell carcinoma.

To explore the role of cytokines in tumor development and clinical manifestations, we examined the expressions of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in tumor tissues obtained from 57 patients with oral squamous cell carcinoma (OSCC) and their relationships to pathological grade and staging. Enzyme-linked immunosorbent assay on the tumor tissues demonstrated elevated concentrations of TNF-alpha and IL-6 proteins and upregulated mRNA levels were detected by the reverse transcription-polymerase chain reaction method when compared to those in normal control tissues. These cytokines and their transcripts were localized in stromal macrophages and in the tumor cells in particular of the front area of tumor tissues, possibly indicating active synthesis of these cytokines by tumor cells. Larger-sized tumors (T3, 4) contained significantly greater levels of IL-6 proteins than small-sized tumors (T1, 2) (P<0.05). The levels of these cytokines were significantly reduced in cases with effective pre-treatment with radiation or anti-cancer agents compared to those in the less effective group (P<0.05, grade IIa vs. grade IV for both TNF-alpha and IL-6). The present study thus demonstrated enhanced expression of cytokines in OSCC tissues.

An actin point-mutation neighboring the 'hydrophobic plug' causes defects in the maintenance of cell polarity and septum organization in the fission yeast Schizosaccharomyces pombe.

The fission yeast cps8 mutation gives rise to abnormally enlarged and dispolarized cells, each of which contains several nuclei with aberrant multisepta. Molecular cloning and sequence analysis of the cps8 gene indicated that it encodes an actin with an amino acid substitution of aspartic acid for glycine at residue 273 in the hydrophobic loop that is located between actin subdomains 3 and 4. Fluorescence microscopy using phalloidin and anti-actin antibody revealed changes in the F-actin structure and distribution in the mutant cells. These results indicate that the hydrophobic loop plays an essential role for creating normal F-actin structure, only by which cell polarity and the late mitotic events can be maintained properly.

A practical method for fission yeast transformation by electroporation.

High-voltage shock within a very short duration under the proper conditions causes cells to incorporate exogenous macromolecules. This technique, electroporation, has been widely used in recent years to transform many organisms. We determined optimum conditions for fission yeast transformation using this method. Of nineteen combinations of electric field strength and pulse time examined, 1.75 kV/0.2 cm, 4 msec pulse was found to provide approximately 4.0 x 10(5) transformants per micrograms of DNA. Other factors responsible for the transformation efficiency in fission yeast are also discussed.

The fertilization potential provides a fast block to polyspermy in lamprey eggs.

At fertilization, the membrane potential of the egg of the lamprey, Lampetra japonica, shifted rapidly from its resting value of -12 to +36 mV and gradually returned to about the same resting level (fertilization potential). The amplitude of depolarization was influenced by the external Cl- concentration and by an anion channel blocker, DIDS, indicating that the positive shift of membrane potential resulted from Cl- efflux. A similar change in membrane potential (activation potential) was observed when the unfertilized egg was pricked with a fine needle or treated with A23187 to induce parthenogenetic activation. Pricking at the animal pole region (predetermined site for sperm entry) resulted in the occurrence of an immediate activation potential and the initiation of cortical granule exocytosis. A time lag between the pricking and the occurrence of the activation potential was observed when the egg was pricked at a distance from the animal pole. In this instance, the activation potential was produced immediately before the propagating cortical granule exocytosis initiated at the pricked site reached the animal pole region. Sperm-egg fusion was blocked in eggs voltage-clamped at +20 to +40 mV and inseminated, whereas it took place in eggs clamped at -60 to 0 mV. However, most eggs clamped at +20 to +40 mV did activate, indicating that the voltage dependence of egg activation differs from that of sperm-egg fusion. Although eggs voltage-clamped at negative membrane potentials permitted multiple sperm to fuse with the egg plasma membrane, the nucleus of the fused sperm did not necessarily enter the ooplasm. We conclude that: (1) A fast electrical block against polyspermy operates in this species and is effective for about 160 sec of the onset of the positive shift; (2) the opening of Cl- channels is responsible for the potential change; (3) the channels are largely localized in the animal pole region; (4) during voltage clamp at positive potentials, eggs can be activated without sperm-egg fusion; and (5) during voltage clamp at negative potentials, sperm-egg fusion occurs, but sperm entry into the egg cytoplasm does not always proceed.

Strontium-phosphate hydroxyapatite high-performance liquid chromatography.

High-performance liquid chromatography using spherical aggregates of strontium-phosphate hydroxyapatite(SrHA) micro-crystals as adsorbent has been developed; preliminary performance tests were carried out by using several types of protein. It can be deduced that, in parallel with the case of usual calcium-phosphate hydroxyapatite(CaHA), with SrHA also, two types of effective surface, vector a (or vector b) and vector c surfaces, appear on the crystal: the same protein molecular generally shows slightly different chromatographic behaviors between the CaHA and the SrHA packed column. Combining the SrHA and the CaHA packed column would lead to an efficient fractionation of a particular molecule from an assembly of molecules with subtle structural differences from one another.

High-performance liquid chromatography using novel square tile-shaped hydroxyapatite crystals as adsorbent.

High-performance liquid chromatography using, as adsorbent, novel square tile-shaped hydroxyapatite crystals (with thicknesses of about 2 microns and diameters of 3-7 microns) has been developed. The chromatographic efficiencies of the novel hydroxyapatite packed columns are almost equal to those of the previously developed spherical hydroxyapatite packed columns; high chromatographic resolutions can be obtained by using extremely reduced column lengths of 0.5-3 cm. Since both the square and the spherical hydroxyapatite have roughly the same particle size of some micrometers, the chromatographic efficiency can be deduced to be determined mainly by the particle size rather than the particle shape.

High-performance liquid chromatography using spherical aggregates of hydroxyapatite micro-crystals as adsorbent.

High-performance liquid chromatography (HPLC) using spherical aggregates of hydroxyapatite (HA) microcrystals as adsorbent has been developed; preliminary performance tests were carried out by using several types of protein. In comparison with previously developed plate-like HA packed columns for HPLC, spherical HA packed columns show considerably high chromatographic resolutions in spite of extremely reduced column lengths of 0.5-3 cm. The pressure generated by the latter columns is much higher than that generated by the former, however.