101 research outputs found
Capability of Tissue Stem Cells to Organize into Salivary Rudiments
Branching morphogenesis (BrM), an essential step for salivary gland development, requires epithelial-mesenchymal interactions. BrM is impaired when the surrounding mesenchyme is detached from the salivary epithelium during the pseudoglandular stage. It is believed that the salivary mesenchyme is indispensable for BrM, however, an extracellular matrix gel with exogenous EGF can be used as a substitute for the mesenchyme during BrM in the developing salivary epithelium. Stem/progenitor cells isolated from salivary glands in humans and rodents can be classified as mesenchymal stem cell-like, bone-marrow-derived, duct cell-like, and embryonic epithelium-like cells. Salivary-gland-derived progenitor (SGP) cells isolated from duct-ligated rats, mice, and swine submandibular glands share similar characteristics, including intracellular laminin and α6ÎČ1-integrin expression, similar to the embryonic salivary epithelia during the pseudoglandular stage. Progenitor cells also isolated from human salivary glands (human SGP cells) having the same characteristics differentiate into hepatocyte-like cells when transplanted into the liver. Similar to the dissociated embryonic salivary epithelium, human SGP cells aggregate to self-organize into branching organ-like structures on Matrigel plus exogenous EGF. These results suggest the possibility that tissue stem cells organize rudiment-like structures, and the embryonic cells that organize into whole tissues during development are preserved even in adult tissues
Negative regulation of hepatitis B virus replication by forkhead box protein A in human hepatoma cells
AbstractHepatitis B virus (HBV) replication is controlled by liver-enriched transcriptional factors, including forkhead box protein A (FOXA) members. Here, we found that FOXA members are directly and indirectly involved in HBV replication in human hepatic cells. HBV replication was elevated in HuH-7 treated with individual FOXA members-specific siRNA. Reciprocally, the downregulation of HBV replication was observed in FOXA-induced HuH-7. However, the mechanism of downregulation is different among FOXA members at the level of HBV RNA transcription, such as precore/pg RNA and 2.1kb RNA. In addition, FOXA1 and FOXA2 suppressed nuclear hormone receptors, such as HNF4α, that are related to HBV replication
A Pivotal Role for Interleukin-27 in CD8+ T Cell Functions and Generation of Cytotoxic T Lymphocytes
Cytotoxic T lymphocytes (CTLs) play a critical role in the control of various cancers and infections, and therefore the molecular mechanisms of CTL generation are a critical issue in designing antitumor immunotherapy and vaccines which augment the development of functional and long-lasting memory CTLs. Interleukin (IL)-27, a member of the IL-6/IL-12 heterodimeric cytokine family, acts on naive CD4+ T cells and plays pivotal roles as a proinflammatory cytokine to promote the early initiation of type-1 helper differentiation and also as an antiinflammatory cytokine to limit the T cell hyperactivity and production of pro-inflammatory cytokines. Recent studies revealed that IL-27 plays an important role in CD8+ T cells as well. Therefore, this article reviews current understanding of the role of IL-27 in CD8+ T cell functions and generation of CTLs
Simulations of Wide-Field Weak Lensing Surveys II: Covariance Matrix of Real Space Correlation Functions
Using 1000 ray-tracing simulations for a {\Lambda}-dominated cold dark model
in Sato et al. (2009), we study the covariance matrix of cosmic shear
correlation functions, which is the standard statistics used in the previous
measurements. The shear correlation function of a particular separation angle
is affected by Fourier modes over a wide range of multipoles, even beyond a
survey area, which complicates the analysis of the covariance matrix. To
overcome such obstacles we first construct Gaussian shear simulations from the
1000 realizations, and then use the Gaussian simulations to disentangle the
Gaussian covariance contribution to the covariance matrix we measured from the
original simulations. We found that an analytical formula of Gaussian
covariance overestimates the covariance amplitudes due to an effect of finite
survey area. Furthermore, the clean separation of the Gaussian covariance
allows to examine the non-Gaussian covariance contributions as a function of
separation angles and source redshifts. For upcoming surveys with typical
source redshifts of z_s=0.6 and 1.0, the non-Gaussian contribution to the
diagonal covariance components at 1 arcminute scales is greater than the
Gaussian contribution by a factor of 20 and 10, respectively. Predictions based
on the halo model qualitatively well reproduce the simulation results, however
show a sizable disagreement in the covariance amplitudes. By combining these
simulation results we develop a fitting formula to the covariance matrix for a
survey with arbitrary area coverage, taking into account effects of the
finiteness of survey area on the Gaussian covariance.Comment: 12 pages, 12 figures, accepted for publication in the Astrophysical
Journal. Simulation data (1000 convergence power spectra and cosmic shear
correlation functions for {\xi}+({\theta}) and {\xi}-({\theta})) are
available upon request (contact [email protected]
IMPACT OF UNCOVERED STENT STRUTS ON OPTICAL COHERENCE TOMOGRAPHY (OCT) DETECTED THROMBUS FORMATION AT 10-MONTH FOLLOW-UP OF SIROLIMUS-ELUTING STENTS (SES)
Impact of Statin Therapy on Plaque Characteristics as Assessed by Serial OCT, Grayscale and Integrated BackscatterâIVUS
ObjectivesThe purpose of this study was to evaluate the effect of statin treatment on coronary plaque composition and morphology by optical coherence tomography (OCT), grayscale and integrated backscatter (IB) intravascular ultrasound (IVUS) imaging.BackgroundAlthough previous studies have demonstrated that statins substantially improve cardiac mortality, their precise effect on the lipid content and fibrous cap thickness of atherosclerotic coronary lesions is less clear. While IVUS lacks the spatial resolution to accurately assess fibrous cap thickness, OCT lacks the penetration of IVUS. We used a combination of OCT, grayscale and IB-IVUS to comprehensively assess the impact of pitavastatin on plaque characteristics.MethodsProspective serial OCT, grayscale and IB-IVUS of nontarget lesions was performed in 42 stable angina patients undergoing elective coronary intervention. Of these, 26 received 4 mg pitavastatin after the baseline study; 16 subjects who refused statin treatment were followed with dietary modification alone. Follow-up imaging was performed after a median interval of 9 months.ResultsGrayscale IVUS revealed that in the statin-treated patients, percent plaque volume index was significantly reduced over time (48.5 ± 10.4%, 42.0 ± 11.1%; p = 0.033), whereas no change was observed in the diet-only patients (48.7 ± 10.4%, 50.4 ± 11.8%; p = NS). IB-IVUS identified significant reductions in the percentage lipid volume index over time (34.9 ± 12.2%, 28.2 ± 7.5%; p = 0.020); no change was observed in the diet-treated group (31.0 ± 10.7%, 33.8 ± 12.4%; p = NS). While OCT demonstrated a significant increase in fibrous cap thickness (140 ± 42 ÎŒm, 189 ± 46 ÎŒm; p = 0.001), such changes were not observed in the diet-only group (140 ± 35 ÎŒm, 142 ± 36 ÎŒm; p = NS). Differences in the changes in the percentage lipid volume index (â6.8 ± 8.0% vs. 2.8 ± 9.9%, p = 0.031) and fibrous cap thickness (52 ± 32 ÎŒm vs. 2 ± 22 ÎŒm, p < 0.001) over time between the pitavastatin and diet groups were highly significant.ConclusionsStatin treatment induces favorable plaque morphologic changes with an increase in fibrous cap thickness, and decreases in both percentage plaque and lipid volume indexes
Applicability of the Movement Assessment Battery for Children-Second Edition (MABC-2) for Japanese Children Aged 3â6 Years: A Preliminary Investigation Emphasizing Internal Consistency and Factorial Validity
This study investigated the applicability of the Movement Assessment Battery for Children â Second Edition (MABC-2) for 3- to 6-year-old Japanese children, particularly addressing its internal consistency and factorial validity. The MABC-2 test set for 3- to 6-year-old children was administered to 252 children. Differences between Japanese children and those of the original normative sample (i.e. United Kingdom children) were investigated along with sex differences. The Japanese children aged 3â6 years were found to have higher Manual Dexterity and Balance component scores than children of the normative sample. Girls scored higher than boys on the Balance component. Results of several analyses showed good internal consistency of the MABC-2. Confirmatory factor analysis revealed that a theoretical three-component model of the MABC-2 was not fitted to Japanese children aged 3â6 years. Instead, a new three-component model was postulated and discussed. The new three-component model of the MABC-2, with Manual Dexterity, Static Balance and Ball Skills, and Dynamic Balance, has high factorial validity in Japanese children aged 3â6 years
Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe
The Extragalactic Background Light (EBL) includes photons with wavelengths
from ultraviolet to infrared, which are effective at attenuating gamma rays
with energy above ~10 GeV during propagation from sources at cosmological
distances. This results in a redshift- and energy-dependent attenuation of the
gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts
(GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray
blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using
photons above 10 GeV collected by Fermi over more than one year of observations
for these sources, we investigate the effect of gamma-ray flux attenuation by
the EBL. We place upper limits on the gamma-ray opacity of the Universe at
various energies and redshifts, and compare this with predictions from
well-known EBL models. We find that an EBL intensity in the optical-ultraviolet
wavelengths as great as predicted by the "baseline" model of Stecker et al.
(2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication
in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A.
Reimer, L.C. Reye
Cardiac Conduction Disorders as Markers of Cardiac Events in Myotonic Dystrophy Type 1.
Background Myotonic dystrophy type 1 involves cardiac conduction disorders. Cardiac conduction disease can cause fatal arrhythmias or sudden death in patients with myotonic dystrophy type 1. Methods and Results This study enrolled 506 patients with myotonic dystrophy type 1 (aged â„15 years; >50 cytosine-thymine-guanine repeats) and was treated in 9 Japanese hospitals for neuromuscular diseases from January 2006 to August 2016. We investigated genetic and clinical backgrounds including health care, activities of daily living, dietary intake, cardiac involvement, and respiratory involvement during follow-up. The cause of death or the occurrence of composite cardiac events (ie, ventricular arrhythmias, advanced atrioventricular blocks, and device implantations) were evaluated as significant outcomes. During a median follow-up period of 87 months (Q1-Q3, 37-138 months), 71 patients expired. In the univariate analysis, pacemaker implantations (hazard ratio [HR], 4.35; 95% CI, 1.22-15.50) were associated with sudden death. In contrast, PQ interval â„240 ms, QRS duration â„120 ms, nutrition, or respiratory failure were not associated with the incidence of sudden death. The multivariable analysis revealed that a PQ interval â„240 ms (HR, 2.79; 95% CI, 1.9-7.19, P<0.05) or QRS duration â„120 ms (HR, 9.41; 95% CI, 2.62-33.77, P < 0.01) were independent factors associated with a higher occurrence of cardiac events than those observed with a PQ interval <240 ms or QRS duration <120 ms; these cardiac conduction parameters were not related to sudden death. Conclusions Cardiac conduction disorders are independent markers associated with cardiac events. Further investigation on the prediction of occurrence of sudden death is warranted
Percutaneous Cryoablation of Pulmonary Metastases from Colorectal Cancer
Objective: To evaluate the safety and efficacy of cryoablation for metastatic lung tumors from colorectal cancer. Methods: The procedures were performed on 24 patients (36â82 years of age, with a median age of 62; 17 male patients, 7 female patients) for 55 metastatic tumors in the lung, during 30 sessions. The procedural safety, local progression free interval, and overall survival were assessed by follow-up computed tomographic scanning performed every 3â4 months. Results: The major complications were pneumothorax, 19 sessions (63%), pleural effusion, 21 sessions (70%), transient and self-limiting hemoptysis, 13 sessions (43%) and tract seeding, 1 session (3%). The 1- and 3-year local progression free intervals were 90.8 % and 59%, respectively. The 3-years local progression free intervals of tumors #15 mm in diameter was 79.8 % and that of tumors.15 mm was 28.6 % (p = 0.001; log-rank test). The 1- and 3-year overall survival rates were 91% and 59.6%, respectively. Conclusion: The results indicated that percutaneous cryoablation is a feasible treatment option. The local progression fre
- âŠ