Analysis of subgingival microbiota in monozygotic twins with different severity and progression risk of periodontitis.

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression.

Microbiome composition comparison in oral and atherosclerotic plaque from patients with and without periodontitis.

There is no conclusive evidence regarding a causal relationship between periodontitis and atherosclerosis. In this study, we examined the microbiome in the oral cavity and atheromatous plaques from atherosclerosis patients with or without periodontitis to investigate the role of oral bacteria in the formation of atheromatous plaques. We chose four patients with and without periodontitis, who had undergone carotid endarterectomy. Bacterial samples were extracted from the tongue surface, from periodontal pocket (during the oral examination), and from the atheromatous plaques (APs). We investigated the general and oral conditions from each patient and performed next-generation sequencing (NGS) analysis for all bacterial samples. There were no significant differences between both groups concerning general conditions. However, the microbiome patterns of the gingival pocket showed differences depending on the absence or presence of periodontitis, while those of the tongue surface were relatively similar. The microbiome pattern of the atheromatous plaques was entirely different from that on the tongue surface and gingival pocket, and oral bacteria were seldom detected. However, the microbiome pattern in atheromatous plaques was different in the presence or absence of periodontitis. These results suggested that oral bacteria did not affect the formation of atheromatous plaques directly.

Acute Prevertebral Abscesses Caused by Bacterial-infected Traumatic Tooth Fractures.

We report a case of acute prevertebral abscess caused by traumatic tooth fractures in a 77-year-old Japanese man. After being transferred to our hospital the patient was initially diagnosed with a neck hematoma; however, blood culture showed Streptococcus parasanguinis, an oral bacterium, and an MRI examination suggested prevertebral abscesses. Tooth fractures, severe periodontitis, and peri-implantitis with Streptococcus parasanguinis were observed. Antibiotics were administered and fractured teeth were extracted. The patient's condition then gradually improved. We concluded that bacteremia caused by traumatic tooth fractures induced the acute prevertebral abscesses.

Multidisciplinary clinical approach by sharing oral examination information to treat a diabetes patient with dysgeusia.

Taste alteration is one of the complications of severe diabetes. It is important in diabetes treatment to assess taste alteration and perform dietary counseling, therapeutic exercise, and oral care. In this case, multidisciplinary clinical approach by medical staff was successful for a severely diabetic patient with dysgeusia.

Assessment of pathogenesis of infective endocarditis by plasma IgG antibody titer test against periodontal bacteria.

Oral bacteria cause infective endocarditis (IE), so severe periodontitis is thought to be high risk for IE. We suggest the identification of high-risk patients by an IgG antibody titer test against periodontal bacteria might become common screening test.

Distribution of oral mucosal bacteria with mecA in patients undergoing hematopoietic cell transplantation.

PURPOSE: We recently reported frequent detection of antibiotic-resistant bacteria on the oral mucosa during the period of hematopoietic cell transplantation (HCT) and suggested an association between oral mucositis and antibiotic-resistant bacterial infection. Methicillin-resistant Staphylococcus spp. were frequently detected, and the oral cavity may be a reservoir of the gene mediating methicillin resistance, mecA. Here, we examined the frequency of mecA carriers in patients undergoing HCT. METHODS: Fifty-nine patients (male (M) = 37, female (F) = 22, 47.3 ± 11.0 years) receiving HCT were enrolled in this study. Buccal swab samples were obtained four times from day -7 to day +20 (once/week), and mecA was detected by PCR. Fifty-two subjects without systemic disease, who completed dental treatment, especially periodontal treatment (M = 21, F = 31, 55.4 ± 14.2 years), were also enrolled as controls and checked for mecA on the oral mucosa. RESULTS: Seventy-six percent (45/59) of the HCT patients carried mecA at least once in the study period (days -7 to +20), while no control subjects had mecA. The frequency of mecA carriers was 19.2 % from days -7 to -1, while it was significantly increased on days +7 to +13 and +14 to +20, with frequencies of 60.9 and 63.2 %, respectively (P < 0.01, ANOVA). CONCLUSIONS: mecA was detected in oral mucosa of patients undergoing HCT. The high detection frequency of staphylococci resistant to penicillin and beta-lactams in our recent report was supported.

Effect of film thickness on the phase behaviors of diblock copolymer thin film.

A phase diagram was constructed for a polystyrene-block-polyisoprene (PS-b-PI, M(W) = 32 700, f(PI) = 0.670) in thin films on Si wafer as a function of film thickness over the range of 150-2410 nm (7-107L(0) (L(0): domain spacing)). The PS-b-PI exhibits a variety of ordered phases from hexagonally perforated lamellar (HPL) via double gyroid (DG) to hexagonally packed cylinder (HEX) before going to the disordered (DIS) phase upon heating. The morphology of the PS-b-PI in thin film was investigated by grazing incidence small-angle X-ray scattering, transmission electron microscopy, and transmission electron microtomography. In thin film, the phase transition temperature is difficult to be determined unequivocally with in situ heating processes since the phase transition is slow and two phases coexist over a wide temperature range. Therefore, in an effort to find an "equilibrium" phase, we determined the long-term stable phase formed after cooling the film from the DIS phase to a target temperature and annealing for 24 h at the temperature. The temperature windows of stable ordered phases are strongly influenced by the film thickness. As the film thickness decreases, the temperature window of layer-like structures such as HPL and HEX becomes wider, whereas that of the DG stable region decreases. For the films thinner than 160 nm (8L(0)), only the HPL phase was found. In the films exhibiting DG phase, a perforated layer structure at the free surface was found, which gradually converts to the internal DG structure. The relief of interfacial tension by preferential wetting appears to play an important role in controlling the morphology in very thin films.

Grating-assisted spectrally-narrowed emissions from an organic slab crystal excited with a mercury lamp.

We report spectrally-narrowed emissions that take place from an organic semiconductor slab crystal of 2,5-bis(4-biphenylyl)thiophene (BP1T) under a low excitation-intensity regime. These emissions are caused with a mercury lamp that operates on a household power supply with an electric current approximately 1 A. The BP1T slab crystal is equipped with a distributed Bragg reflector. To complete this structure the slab crystal is attached to a diffraction grating that is engraved on a surface of a quartz glass substrate. The diffraction gratings have precisely been formed using a focused ion beam with a nanometer-defined precision. The spectral narrowing accompanied by the emission intensity increment is related to the strong mode-coupling between the forward electromagnetic wave and the backward (i.e., reflected) wave within the grating zone. Using a laser we also carried out the emission measurements on the BP1T crystals under a high excitation-intensity regime. The emissions are characterized as the longitudinal multimode laser oscillation, enabling us to determine the group refractive index of 4.56 for the BP1T slab crystal. Under both the low and high excitation-intensity regimes excitons are dominant species of the emission. Their participation in the spectrally-narrowed emissions is briefly discussed.

Small-molecule-directed nanoparticle assembly towards stimuli-responsive nanocomposites.

Precise control of the spatial organization of nanoscopic building blocks, such as nanoparticles, over multiple length scales is a bottleneck in the 'bottom-up' generation of technologically important materials. Only a few approaches have been shown to achieve nanoparticle assemblies without surface modification. We demonstrate a simple yet versatile approach to produce stimuli-responsive hierarchical assemblies of readily available nanoparticles by combining small molecules and block copolymers. Organization of nanoparticles into one-, two- and three-dimensional arrays with controlled inter-particle separation and ordering is achieved without chemical modification of either the nanoparticles or block copolymers. Nanocomposites responsive to heat and light are demonstrated, where the spatial distribution of the nanoparticles can be varied by exposure to heat or light or changing the local environment. The approach described is applicable to a wide range of nanoparticles and compatible with existing fabrication processes, thereby enabling a non-disruptive approach for the generation of functional devices.

New epitaxial phase transition between DG and HEX in PS-b-PI.

We investigated the epitaxial phase transition from double gyroid (DG) to hexagonally packed cylinder (HEX) phases of a polystyrene-b-polyisoprene diblock copolymer in a thin film on a Si wafer substrate. The internal structure of the thin film was investigated by grazing incidence small-angle X-ray scattering, transmission electron microscopy, and transmission electron microtomography (TEMT). TEMT allows observation of the 3D-image of coexisting DG and HEX directly. Good domain orientation in the thin film and direct 3D-imaging of TEMT made it possible to observe the coexisting phase of DG and HEX, and a new epitaxial transition path from DG to HEX was found.