337 research outputs found
Mandibular odontogenic cyst atypically extended into the submandibular region with thickened bone formation: A case report
Kodama S., Uchihashi T., Shimamoto H., et al. Mandibular odontogenic cyst atypically extended into the submandibular region with thickened bone formation: A case report. Oral Science International , (2024); https://doi.org/10.1002/osi2.1228.Background: Odontogenic cysts can cause thinning and expansion of the surrounding cortical bone; however, bone formation extending into the submandibular region, resembling periosteal reactions, is rarely observed in odontogenic cysts. Case Presentation: A 52-year-old man presented with painful submandibular swelling and dyspnea. Computed tomography revealed an extensive mandibular cystic lesion extending to the submandibular region accompanied by thickened bone formation, mimicking lobulated shell-type periosteal reaction. Percutaneous cystectomy with extensive mandibular bone resection was performed. Conclusion: Prolonged existence of extensive cystic lesion and inflammatory stimulation may result in bone elongation into the submandibular region, mimicking periosteal reaction
Simulations of Surface X-ray Diffraction from a Monolayer 4He Film Adsorbed on Graphite
We carried out simulations of crystal truncation rod (CTR) scatterings, i.e.,
one of the surface X-ray diffraction techniques with atomic resolution, from a
monolayer He film adsorbed on graphite. Our simulations reveal that the 00L rod
scatterings from the He monolayer exhibit notable intensity modifications for
those from a graphite surface in the ranges of approximately L = 0.6 - 1.7 and
L = 2.2 - 3.5. The height of the He monolayer from the graphite surface largely
affects the CTR scattering profiles, indicating that CTR scatterings have
enough sensitivities to determine the surface structure of the various phases
in the He layer. In particular, in the incommensurate solid phase, our
preliminary experimental data show the intensity modulations that are expected
from the present simulations.Comment: 6 pages, 4 figures, to be published in JPS Conf. Pro
A study of the seismic effects on a portal frame having a hole at the beam-column connection
This paper presents the results of the study on thin walled steel portal frames, which are used in Japan as basic structural frames for motorway viaducts. A serious problem found in many such frames is the development of fatigue cracks at the beam to column connection. To act as a measure against the fatigue failure, in some cases a hole is provided at the beam-column connection of the frames. In this study, dynamic analysis using real earthquake data from 3 different earthquakes were carried out to examine the influence of such a hole on the global behavior of the frame and also on the local out of plane displacement around the location of the hole. Non-linear, large displacement analysis was performed using the FEM program MSC. Marc. The hole radius was varied and used as a parameter of study. The hole had significant effect on local out of plane displacement and global behavior, specifically when the radius of the hole was larger than 100 mm.ArticleTHIN-WALLED STRUCTURES. 52:53-60 (2012)journal articl
Clear Cell Squamous Cell Carcinoma of the Maxillary Gingiva Associated with PIK3CA and HRAS Mutations: Report of a Case and Literature Review
The version of record of this article, first published in Head and Neck Pathology, is available online at Publisher’s website: https://doi.org/10.1007/s12105-023-01580-8.Background: Squamous cell carcinoma (SCC) is the most common oral malignancy, and somatic mutations in some driver genes have been implicated in SCC development. Clear cell SCC (CCSCC) is a rare histological variant of SCC, and various clear cell neoplasms must be considered in the differential diagnosis of CCSCC in the oral cavity. Based on a limited number of CCSCC cases reported in the oral cavity, CCSCC is considered an aggressive variant of SCC with a poor prognosis; however, its genetic characteristics remain unknown. Methods: A maxillary gingival tumor in an 89-year-old female was described and investigated using immunohistochemical staining, special staining, fluorescence in situ hybridization, and next-generation sequencing (NGS) with a custom panel of driver genes, including those associated with SCC and clear cell neoplasm development. Results: Histopathological examination revealed a proliferation of atypical epithelial cells with abundant clear cytoplasm and enlarged and centrally placed round nuclei. The tumor was exophytic with deep, penetrating proliferation. The atypical clear cells were continuous with the conventional SCC cells. Immunohistochemical analysis showed that the clear cells were positive for CK AE1/AE3 and CK5/6 and nuclear-positive for p63. In contrast, the clear cells were negative for αSMA, S100, HMB45, Melan-A, CD10, and p16. p53 immunoreactivity exhibited a wild-type expression pattern. Additionally, the clear cells were positive for periodic acid-Schiff (PAS) and negative for diastase-PAS, mucicarmine, and Alcian blue. Based on these results, the diagnosis of CCSCC was confirmed. Molecular analysis of the clear cells identified PIK3CA p.E542K (c.1624G>A) and HRAS p.G12A (c.35 G>C) somatic mutations classified as oncogenic. No pathogenic variants were identified in TP53, EWSR1, AKT1, PTEN, BRAF, KRAS, NRAS, RASA1, or MAML2. Conclusions: We report a case of CCSCC of the oral cavity with PIK3CA and HRAS mutations. The identification of PIK3CA and/or HRAS mutations is rare in SCC; however, both mutations are important potential targets for antitumor therapy. A detailed analysis of gene mutations in CCSCC may lead to a better understanding of its biological behavior and an improved prognosis, as well as a differential diagnosis from other clear cell neoplasms
Dynamical structure factors of the magnetization-plateau state in the bond-alternating spin chain with a next-nearest-neighbor interaction
We calculate the dynamical structure factors of the magnetization-plateau
state in the bond-alternating spin chain with a next-nearest-neighbor
interaction. The results show characteristic behaviors depending on the
next-nearest-neighbor interaction and the bond-alternation .
We discuss the lower excited states in comparison with the exact excitation
spectrums of an effective Hamiltonian. From the finite size effects,
characteristics of the lowest excited states are investigated. The
dispersionless mode of the lowest excitation appears in adequate sets of
and , indicating that the lowest excitation is localized
spatially and forms an isolated mode below the excitation continuum. We further
calculate the static structure factors. The largest intensity is located at
for small in fixed . With increasing , the
wavenumber of the largest intensity shifts towards , taking the
incommensurate value.Comment: to appear in Phys. Rev. B (2001
Histone deacetylase 5 regulates the inflammatory response of macrophages
Modifying the chromatin structure and interacting with non-histone proteins,
histone deacetylases (HDAC) are involved in vital cellular processes at
different levels. We here specifically investigated the direct effects of
HDAC5 in macrophage activation in response to bacterial or cytokine stimuli.
Using murine and human macrophage cell lines, we studied the expression
profile and the immunological function of HDAC5 at transcription and protein
level in over-expression as well as RNA interference experiments. Toll-like
receptor-mediated stimulation of murine RAW264.7 cells significantly reduced
HDAC5 mRNA within 7 hrs but presented baseline levels after 24 hrs, a
mechanism that was also found for Interferon-γ treatment. If treated with
lipopolysaccharide, RAW264.7 cells transfected for over-expression only of
full-length but not of mutant HDAC5, significantly elevated secretion of
tumour necrosis factor α and of the monocyte chemotactic protein-1. These
effects were accompanied by increased nuclear factor-κB activity. Accordingly,
knock down of HDAC5-mRNA expression using specific siRNA significantly reduced
the production of these cytokines in RAW264.7 or human U937 cells. Taken
together, our results suggest a strong regulatory function of HDAC5 in the
pro-inflammatory response of macrophages
HYL1 controls the miR156-mediated juvenile phase of vegetative growth
HYL1 is an important regulator of microRNA (miRNA) biogenesis. A loss-of-function mutation of HYL1 causes the reduced accumulation of some miRNAs but fails to display the miRNA-deficient phenotypes of these miRNAs. In Arabidopsis, miR156 mediates phase transition through repression of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL) genes. However, it remains unknown whether, and if so how, HYL1 enables phase transition through miR156. This study showed that a loss-of-function mutation of the HYL1 gene caused defects in the timing of the juvenile phase. In the primary leaves of hyl1-2 mutants, abaxial trichomes were generated prematurely, the leaf blades elongated, and the blade base angles enlarged, as is observed for adult leaves. In hyl1-2 p35S::miR156a and hyl1-2 spl9-4 spl15-1 plants, increased accumulation of miR156a and repressed expression of the SPL genes were concomitant with a complete or partial rescue of the hyl1-2 phenotype in phase defects. In contrast, overexpression of the SPL9 gene in hyl1-2 mutants led to total disappearance of the juvenile phase. Moreover, HYL1 prevented the premature accumulation of adult-related transcripts in the primary leaves. Taken together, these results suggest that HYL1 controls the expression levels of miR156-targeted SPL genes and enables plants to undergo the juvenile phase, an important and critical step during plant development to ensure maximum growth and productivity
Hemorheology and Microvascular Disorders
The present review presents basic concepts of blood rheology related to vascular diseases. Blood flow in large arteries is dominated by inertial forces exhibited at high flow velocities, while viscous forces (i.e., blood rheology) play an almost negligible role. When high flow velocity is compromised by sudden deceleration as at a bifurcation, endothelial cell dysfunction can occur along the outer wall of the bifurcation, initiating inflammatory gene expression and, through mechanotransduction, the cascade of events associated with atherosclerosis. In sharp contrast, the flow of blood in microvessels is dominated by viscous shear forces since the inertial forces are negligible due to low flow velocities. Shear stress is a critical parameter in microvascular flow, and a force-balance approach is proposed for determining microvascular shear stress, accounting for the low Reynolds numbers and the dominance of viscous forces over inertial forces. Accordingly, when the attractive forces between erythrocytes (represented by the yield stress of blood) are greater than the shear force produced by microvascular flow, tissue perfusion itself cannot be sustained, leading to capillary loss. The yield stress parameter is presented as a diagnostic candidate for future clinical research, specifically, as a fluid dynamic biomarker for microvascular disorders. The relation between the yield stress and diastolic blood viscosity (DBV) is described using the Casson model for viscosity, from which one may be able determine thresholds of DBV where the risk of microvascular disorders is high
Antitumor Agents. 282. 2′-( R )- O -Acetylglaucarubinone, a Quassinoid from Odyendyea gabonensis As a Potential Anti-Breast and Anti-Ovarian Cancer Agent
A new quassinoid, designated 2′-(R)-O-acetylglaucarubinone (1), and seven known quassinoids (2–8) were isolated, using bioactivity-guided separation, from the bark of Odyendyea gabonensis (Pierre) Engler [syn. Quassia gabonensis Pierre (Simaroubaceae)]. The structure of 1 was determined by spectroscopic analysis, and by semi-synthesis from glaucarubolone. Complete 1H and 13C NMR assignments of compounds 1–8 were also established from detailed analysis of two-dimensional NMR spectra, and the reported configurations in odyendene (7) and odyendane (8) were corrected. Compound 1 showed potent cytotoxicity against multiple cancer cell lines. Further investigation using various types of breast and ovarian cancer cell lines suggested that 1 does not target the estrogen receptor (ER) or progesterone receptor (PR). When tested against mammary epithelial proliferation in vivo using a Brca1/p53-deficient mice model, 1 also caused significant reduction in mammary duct branching
Clathrin Facilitates the Morphogenesis of Retrovirus Particles
The morphogenesis of retroviral particles is driven by Gag and GagPol proteins that provide the major structural component and enzymatic activities required for particle assembly and maturation. In addition, a number of cellular proteins are found in retrovirus particles; some of these are important for viral replication, but many lack a known functional role. One such protein is clathrin, which is assumed to be passively incorporated into virions due to its abundance at the plasma membrane. We found that clathrin is not only exceptionally abundant in highly purified HIV-1 particles but is recruited with high specificity. In particular, the HIV-1 Pol protein was absolutely required for clathrin incorporation and point mutations in reverse transcriptase or integrase domains of Pol could abolish incorporation. Clathrin was also specifically incorporated into other retrovirus particles, including members of the lentivirus (simian immunodeficiency virus, SIVmac), gammaretrovirus (murine leukemia virus, MLV) and betaretrovirus (Mason-Pfizer monkey virus, M-PMV) genera. However, unlike HIV-1, these other retroviruses recruited clathrin primarily using peptide motifs in their respective Gag proteins that mimicked motifs found in cellular clathrin adaptors. Perturbation of clathrin incorporation into these retroviruses, via mutagenesis of viral proteins, siRNA based clathrin depletion or adaptor protein (AP180) induced clathrin sequestration, had a range of effects on the accuracy of particle morphogenesis. These effects varied according to which retrovirus was examined, and included Gag and/or Pol protein destabilization, inhibition of particle assembly and reduction in virion infectivity. For each retrovirus examined, clathrin incorporation appeared to be important for optimal replication. These data indicate that a number of retroviruses employ clathrin to facilitate the accurate morphogenesis of infectious particles. We propose a model in which clathrin contributes to the spatial organization of Gag and Pol proteins, and thereby regulates proteolytic processing of virion components during particle assembly
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