138 research outputs found
Oral pathobiont induces systemic inflammation and metabolic changes associated with alteration of gut microbiota.
Periodontitis has been implicated as a risk factor for metabolic disorders such as type 2 diabetes, atherosclerotic vascular diseases, and non-alcoholic fatty liver disease. Although bacteremias from dental plaque and/or elevated circulating inflammatory cytokines emanating from the inflamed gingiva are suspected mechanisms linking periodontitis and these diseases, direct evidence is lacking. We hypothesize that disturbances of the gut microbiota by swallowed bacteria induce a metabolic endotoxemia leading metabolic disorders. To investigate this hypothesis, changes in the gut microbiota, insulin and glucose intolerance, and levels of tissue inflammation were analysed in mice after oral administration of Porphyromonas gingivalis, a representative periodontopathogens. Pyrosequencing revealed that the population belonging to Bacteroidales was significantly elevated in P. gingivalis-administered mice which coincided with increases in insulin resistance and systemic inflammation. In P. gingivalis-administered mice blood endotoxin levels tended to be higher, whereas gene expression of tight junction proteins in the ileum was significantly decreased. These results provide a new paradigm for the interrelationship between periodontitis and systemic diseases
Absence of Tc-Pinning Phenomenon Under High Pressure in High-Entropy REO0.5F0.5BiS2 Layered Superconductor
Recently, robustness of superconductivity (transition temperature, Tc) under
high pressures has been observed in high-entropy alloy (HEA), bcc-type
Ti-Zr-Hf-Nb-Ta, and HEA-type compounds (Ag,In,Sn,Pb,Bi)Te with a NaCl-type
structure. Since those materials have three-dimensional crystal structure,
investigation on the pressure dependence of Tc of low-dimensional materials is
needed to understand the phenomena. Here, we investigated the superconducting
properties and the crystal structure of BiS2-based layered system
REO0.5F0.5BiS2. Although the robustness of Tc was induced in MTe with
increasing M-site configurational entropy, the increase in RE-site
configurational entropy does not induce robustness of Tc under high pressures
in REO0.5F0.5BiS2. The crystal structure of HEA-type REO0.5F0.5BiS2 was
confirmed as monoclinic P21/m, which is the same space group as the
zero-entropy counterpart LaO0.5F0.5BiS2. The results suggest that an increase
in configurational entropy at blocking layers do not affect crystal structure
and superconducting properties under high pressures in the BiS2-based layered
system.Comment: 9 pages, 4 figure
Improved methods for detection of β-galactosidase (lacZ) activity in hard tissue
The ß-galactosidase gene (lacZ) of Escherichia coli is widely used as a reporter gene. The expression of lacZ can be detected by enzyme-based histochemical staining using chromogenic substrates such as 5-bromo-4-chloro-3-indolyl-ß-D: -galactoside (X-gal). Because the enzymatic activity of lacZ is vulnerable to high temperatures and acid treatment for demineralization, detection of lacZ on paraffinized sections is difficult, especially for hard tissues, which require demineralization before sectioning in paraffin. To circumvent this problem, whole-mount X-gal staining before sectioning is performed. However, detection of lacZ activity in the center of larger portions of hard whole adult tissues is challenging. In this study, focusing on fixation procedures, we determined the conditions conducive to improved detection of lacZ activity in deeper areas of whole tissues. We used an annexin a5 (Anxa5)-lacZ reporter mouse model in which the Anxa5 expression in hard tissue is indicated by lacZ activity. We found that lacZ activity could be detected throughout the periodontal ligament of adult mice when fixed in 100% acetone, whereas it was not detected in the periodontal ligament around the root apex fixed in glutaraldehyde and paraformaldehyde. This staining could not be detected in wild-type mice. Acetone maintains the lacZ activity within 48 h of fixation at both 4°C and at room temperature. In conclusion, acetone is the optimal fixative to improve permeability for staining of lacZ activity in large volumes of adult hard tissues
Finite-size scaling for the Ising model on the Moebius strip and the Klein bottle
We study the finite-size scaling properties of the Ising model on the Moebius
strip and the Klein bottle. The results are compared with those of the Ising
model under different boundary conditions, that is, the free, cylindrical, and
toroidal boundary conditions. The difference in the magnetization distribution
function for various boundary conditions is discussed in terms of the
number of the percolating clusters and the cluster size. We also find
interesting aspect-ratio dependence of the value of the Binder parameter at
for various boundary conditions. We discuss the relation to the
finite-size correction calculations for the dimer statistics.Comment: 4 pages including 5 eps figures, RevTex, to appear in Phys. Rev. Let
Off-diagonal Gluon Mass Generation and Infrared Abelian Dominance in the Maximally Abelian Gauge in Lattice QCD
We study effective mass generation of off-diagonal gluons and infrared
abelian dominance in the maximally abelian (MA) gauge. Using the SU(2) lattice
QCD, we investigate the propagator and the effective mass of the gluon field in
the MA gauge with the U(1) Landau gauge fixing. The Monte Carlo simulation
is performed on the lattice with , and
also on the and lattices with . In the MA
gauge, the diagonal gluon component shows long-range propagation, and
infrared abelian dominance is found for the gluon propagator. In the MA gauge,
the off-diagonal gluon component behaves as a massive vector boson
with the effective mass GeV in the region of r \gsim
0.2 fm, and its propagation is limited within short range. We conjecture that
infrared abelian dominance can be interpreted as infrared inactivity of the
off-diagonal gluon due to its large mass generation induced by the MA gauge
fixing.Comment: 31 pages, 7 figures and 2 tables included, changed title, corrected
typos and updated reference, accepted for publication in Physical Review
The Nature of Ultra-Luminous Compact X-Ray Sources in Nearby Spiral Galaxies
Studies were made of ASCA spectra of seven ultra-luminous compact X-ray
sources (ULXs) in nearby spiral galaxies; M33 X-8 (Takano et al. 1994), M81 X-6
(Fabbiano 1988b; Kohmura et al. 1994; Uno 1997), IC 342 Source 1 (Okada et al.
1998), Dwingeloo 1 X-1 (Reynolds et al. 1997), NGC 1313 Source B (Fabbiano &
Trinchieri 1987; Petre et al. 1994), and two sources in NGC 4565 (Mizuno et al.
1999). With the 0.5--10 keV luminosities in the range 10^{39-40} ergs/s, they
are thought to represent a class of enigmatic X-ray sources often found in
spiral galaxies. For some of them, the ASCA data are newly processed, or the
published spectra are reanalyzed. For others, the published results are quoted.
The ASCA spectra of all these seven sources have been described successfully
with so called multi-color disk blackbody (MCD) emission arising from
optically-thick standard accretion disks around black holes. Except the case of
M33 X-8, the spectra do not exhibit hard tails. For the source luminosities not
to exceed the Eddington limits, the black holes are inferred to have rather
high masses, up to ~100 solar masses. However, the observed innermost disk
temperatures of these objects, Tin = 1.1--1.8 keV, are too high to be
compatible with the required high black-hole masses, as long as the standard
accretion disks around Schwarzschild black holes are assumed. Similarly high
disk temperatures are also observed from two Galactic transients with
superluminal motions, GRO 1655-40 and GRS 1915+105. The issue of unusually high
disk temperature may be explained by the black hole rotation, which makes the
disk get closer to the black hole, and hence hotter.Comment: submitted to ApJ, December 199
Aesthetic consideration in patient management of severe periodontitis aggravated by oral dexamethasone
Background: The treatment of severe periodontitis must consider immune responses and local conditions, including the aesthetical aspects. The tooth loss in the anterior area can lead to a psychological issue in some patients, and the daily use of dexamethasone contributes greatly to the severity of aesthetical aspects. Periodontal treatments must be cautious of these aesthetical effects. Purpose: To report the aesthetical consideration in patient management of severe periodontitis aggravated by oral dexamethasone. Case: The 44-year-old female patient reported having tooth mobility in the upper right and left central incisor and lower right and left posterior. Due to the condition, the central anterior needed to be extracted. The patient had seafood allergies and consumed oral dexamethasone periodically to prevent allergic reactions for two years. Case management: The initial periodontal therapy was designed prior to the tooth extraction, socket preservation, and immediate denture on teeth 11 and 21. A metal frame combined with an acrylic denture was designed to support the tooth splint and replace the teeth on the mandible. The patient was treated with 20 mg of sub-antimicrobial-dose doxycycline twice a day for three months, and vitamin E was prescribed once a day. Since dexamethasone may contribute to immune response and osteoclastogenesis, dexamethasone was replaced by cetirizine. Conclusion: The treatment of severe chronic periodontitis must consider immune responses, local conditions, and aesthetical aspects. In this case, the use of dexamethasone might worsen the periodontal breakdown. However, the periodontal treatment, use of host modulation therapy, and replacement of dexamethasone with cetirizine are expected to improve these conditions
Treatment of hepatic encephalopathy by on-line hemodiafiltration: a case series study
<p>Abstract</p> <p>Background</p> <p>It is thought that a good survival rate of patients with acute liver failure can be achieved by establishing an artificial liver support system that reliably compensates liver function until the liver regenerates or a patient undergoes transplantation. We introduced a new artificial liver support system, on-line hemodiafiltration, in patients with acute liver failure.</p> <p>Methods</p> <p>This case series study was conducted from May 2001 to October 2008 at the medical intensive care unit of a tertiary care academic medical center. Seventeen consecutive patients who admitted to our hospital presenting with acute liver failure were treated with artificial liver support including daily on-line hemodiafiltration and plasma exchange.</p> <p>Results</p> <p>After 4.9 ± 0.7 (mean ± SD) on-line hemodiafiltration sessions, 16 of 17 (94.1%) patients completely recovered from hepatic encephalopathy and maintained consciousness for 16.4 ± 3.4 (7-55) days until discontinuation of artificial liver support (a total of 14.4 ± 2.6 [6-47] on-line hemodiafiltration sessions). Significant correlation was observed between the degree of encephalopathy and number of sessions of on-line HDF required for recovery of consciousness. Of the 16 patients who recovered consciousness, 7 fully recovered and returned to society with no cognitive sequelae, 3 died of complications of acute liver failure except brain edema, and the remaining 6 were candidates for liver transplantation; 2 of them received living-related liver transplantation but 4 died without transplantation after discontinuation of therapy.</p> <p>Conclusions</p> <p>On-line hemodiafiltration was effective in patients with acute liver failure, and consciousness was maintained for the duration of artificial liver support, even in those in whom it was considered that hepatic function was completely abolished.</p
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