Chemokines Up-Regulated in Epithelial Cells Control Senescence-Associated T Cell Accumulation in Salivary Glands of Aged and Sjögren’s Syndrome Model Mice

Immunosenescence is characterized by age-associated changes in immunological functions. Although age- and autoimmune-related sialadenitis cause dry mouth (xerostomia), the roles of immunosenescence and cellular senescence in the pathogenesis of sialadenitis remain unknown. We demonstrated that acquired immune cells rather than innate immune cells infiltrated the salivary glands (SG) of aged mice. An analysis of isolated epithelial cells from SG revealed that the expression levels of the chemokine CXCL13 were elevated in aged mice. Senescence-associated T cells (SA-Ts), which secrete large amounts of atypical pro-inflammatory cytokines, are involved in the pathogenesis of metabolic disorders and autoimmune diseases. The present results showed that SA-Ts and B cells, which express the CXCL13 receptor CXCR5, accumulated in the SG of aged mice, particularly females. CD4⁺ T cells derived from aged mice exhibited stronger in vitro migratory activity toward CXCL13 than those from young mice. In a mouse model of Sjögren’s syndrome (SS), SA-Ts also accumulated in SG, presumably via CXCL12-CXCR4 signaling. Collectively, the present results indicate that SA-Ts accumulate in SG, contribute to the pathogenesis of age- and SS-related sialadenitis by up-regulating chemokines in epithelial cells, and have potential as therapeutic targets for the treatment of xerostomia caused by these types of sialadenitis.     

Effect of Electron Correlation on Phonon Spectra in Cuprates

We examine theoretically the phonon dynamics in the electron-phonon-coupled systems. The model Hamiltonian is a one-dimensional Hubbard model where the hopping of electrons induces the electron-phonon coupling. The numerically exact diagonalization of the Hamiltonian with truncation of the total number of phonons is performed. We calculate the phonon excitation spectra and find that the softening of phonons occurs in insulating case, and a diffusive character appears in the metallic case. We also calculate the charge and spin excitation spectra and find that the dynamics of the phonon coupled with the hopping of electrons is affected by the low energy charge and spin excitations.     

Optical circulator consisting of a YIG spherical lens, PANDA-fibre polarisers and a fibre-optic polarising beam splitter

A novel optical circulator is reported which employs an yttrium-iron-garnet (YIG) sphere, PANDA-fibre polarisers and a fibre-optic polarising beam splitter. The splitting ratios of the fibre-optic polarising beam splitter were 1.0:99.0 for x-polarisation and 97.5:2.5 for y-polarisation, with an excess loss of 0.5 dB at 1.30 ?m wavelength. The backward isolation of the optical circulator was 30 dB with the total insertion loss of 4.5 dB.     

Markedly compressible behaviors of gellan hydrogels in a constrained geometry at ultraslow strain rates

The fracture behaviors of gellan hydrogels under compression remarkably depend on the strain rate as well as the boundary conditions for lateral expansion. In the geometry with no constraint for lateral expansion (conventional uniaxial compression), the gels rupture at relatively small strains independently of the compression rates. In contrast, when the gels are compressed extremely slowly (at a strain rate of ca. 10⁻⁵ s⁻¹) in the geometry prohibiting the lateral expansion at their top and bottom surfaces, they are remarkably compressible down to 2% of the initial height without macroscopic fracture and they are accompanied by a large amount of water release. In such markedly compressed gels, many microscopic cracks are formed around the central layer, where strain concentration occurs due to the nonuniform deformation arising from the constrained geometry. In the highly compressible case, the formation of macroscopic cracks is prevented by the localization of microscopic cracks as well as the enhancement in mechanical toughness by a significant increase in polymer concentration due to water release.     

Linearity stablized fiber-optic thermometer using pseudo-heterodyne phase detection

A temperature sensor using a fiber-optic Fabry-Perot interferometer is described. A pseudo-heterodyne detection scheme is adopted to read the light phase difference in the Fabry-Perot interference output. A higher harmonic components comparison method is used to stabilize the system and to increase detection linearity. This system realizes not only highly sensitive temperature sensing with good linearity and minimal adjusting error, but also application to the sensing of other physical quantities such as vibrations. Additionally, the signal-to-noise ratio and distortion of the detected signal are investigated as functions of fiber end reflectivity. These results will be useful in designing a high performance fiber-optic Fabry-Perot thermometer.     

Clinical and serological study of tsutsugamushi disease in northern Osumi, Kagoshima Prefecture

We report 34 cases of tsutsugamushi disease seen from 1989 to 1993 at Yagi Clinic, northern Osumi, Kagoshima Prefecture. Nineteen patients (55.9%) showed the highest antibody titers against the Kawasaki strain Orientia tsutsugamushi (Ot) and 13 (38.2%) against the Kuroki strain Ot. It is suggested that two antigenic types (Kawasaki and Kuroki) of Ot were distributed in Kagoshima Prefecture, and the Kawasaki type Ot more or less dominates Kuroki type Ot. There was no difference in clinical features between the two groups of patients.     

Right atrial contractile performance in patients with myocardial infarction

To evaluate right atrial (RA) contractile performance in patients with myocardial infarction, we validated a cineangiographic method of RA volume measurement, and investigated RA volume change in 'normal' individuals and patients with a previous myocardial infarction. Sixteen silicone rubber RA casts made from human cadavers were filmed in the postero-anterior and left lateral projections. The cast volumes calculated following Simpson's rule were in good agreement with those measured by water replacement (r = 0.992, P < 0.01). At cardiac catheterization, biplane RA cineangiography was performed in 19 'normal' individuals (N group), in 14 patients with a previous antero-septal infarction (AMI group) and in seven patients with a previous inferior infarction (IMI group). The RA volume-time curve was constructed at 20-40 ms intervals for one cardiac cycle. RA volume at the beginning of the atrial contraction (RAVd), which was defined as the 'preload' of the RA, tended to be larger in both the AMI and IMI groups compared with 'normal' individuals. The RA ejection volume was significantly larger in both the AMI (18.4 +/- 2.1 ml.m-2, P < 0.01) and IMI groups (19.4 +/- 2.8, P < 0.01) than in the N group (14.5 +/- 1.9), even for a comparable level of RAVd (range from 26 to 36 ml.m-2) (18.6 +/- 2.1, P < 0.01, 18.2 +/- 2.0, P < 0.01, 14.7 +/- 1.9, respectively). These results suggest that RA contraction increases in patients with myocardial infarction by increasing both the 'preload' and 'contractility' of the RA.     

Stabilization of bioethanol recovery with silicone rubber‐coated ethanol‐permselective silicalite membranes by controlling the pH of acidic feed solution

In order to produce highly concentrated bioethanol by pervaporation using an ethanol‐permselective silicalite membrane, techniques to suppress adsorption of succinic acid, which is a chief by‐product of ethanol fermentation and causes the deterioration in pervaporation performance, onto the silicalite crystals was investigated. The amount adsorbed increased as the pH of the aqueous succinic acid solution decreased. The pervaporation performance also decreased with decreasing pH when the ternary mixtures of ethanol/water/succinic acid were separated. Using silicalite membranes individually coated with two types of silicone rubber, pervaporation performance was significantly improved in the pH range of 5 to 7, when compared with that of non‐coated silicalite membranes in ternary mixtures of ethanol/water/succinic acid. Moreover, when using a silicalite membrane double‐coated with the two types of silicone rubber, pervaporation performance was stabilized at lower pH values. In the separation of bioethanol by pervaporation using the double‐coated silicalite membrane, removal of accumulated substances having an ultraviolet absorption maximum at approximately 260 nm from the fermentation broth proved to be vital for efficient pervaporation. Copyright © 2005 Society of Chemical Industry     

Far infrared reflection spectra in narrow-gap semiconductors

Far infrared reflection spectra of Cd_XHg_1?X Se are measured in the region 20 to 600 cm^?1 at temperatures between 5 and 77 K. Reflection spectra are explained well by the dynamic dielectric function which is constructed as a sum of Γ₈?Γ₈ interband, intraband and phonon contributions. The plasmon-LO phonon coupling effect is also discussed.