2,193 research outputs found
Endovascular Treatment for Intracranial Aneurysms: A Nationwide Survey in Korea
Purpose In Korea, endovascular treatment (EVT) for intracranial aneurysms (IAs) has increased steadily. We conducted a nationwide survey to evaluate the current status of EVT for IAs and to identify treatment preference in the real world.Materials and Methods A Google online survey was distributed to representative clinicians at hospitals treating IAs, where members of Korean Society of Interventional Neuroradiology (KSIN). The data was collected from October 2017 to December 2017. The responding hospitals were divided into 2 groups (tertiary and non-tertiary hospitals). And variable factors involved in decision making for treatment were evaluated. Results In total, 73 hospitals (tertiary: 37, non-tertiary: 36) responded to the survey. Most hospitals that responded had over 100 cases of diagnostic angiography (93%) and over 50 cases of EVT for IAs (74%) performed in 2016. The proportion of EVT for ruptured aneurysms in non-tertiary hospitals was significantly higher than tertiary hospitals (49% vs. 9%). The proportion of EVT for unruptured aneurysms at non-tertiary hospitals was significantly higher than tertiary hospitals (66% vs. 44%). Most physicians tended to make decision for treatment on location, shape, and size of unruptured IAs and patients’ age, more than the results from previous clinical trials for unruptured IAs. Although EVT was preferred for older patients (age >70) with unruptured IAs (99%), surgical clipping was still considered as the first treatment of choice for younger patients (age 30 to 50 years) at considerable rates (56%). Over two-thirds of respondents preferred surgical clipping for middle cerebral artery aneurysms, while EVT was preferred initially at other locations. Conclusion This nationwide survey showed that EVT is considered as the first treatment modality for IAs and there is a discrepancy between current guidelines and real-world practice for decision making of treatment options
Mean flow characteristics of two-dimensional wings in ground effect
ABSTRACTThe present study numerically investigates the aerodynamic characteristics of two-dimensional wings in the vicinity of the ground by solving two-dimensional steady incompressible Navier-Stokes equations with the turbulence closure model of the realizable k-ε model. Numerical simulations are performed at a wide range of the normalized ground clearance by the chord length (0.1≤h/C ≤ 1.25) for the angles of attack (0° ≤ α ≤ 10°) in the pre-stall regime at a Reynolds number (Re) of 2×106 based on free stream velocity U∞ and the chord length. As the physical model of this study, a cambered airfoil of NACA 4406 has been selected by a performance test for various airfoils. The maximum lift-to-drag ratio is achieved at α = 4° and h/C = 0.1. Under the conditions of α = 4° and h/C = 0.1, the effect of the Reynolds number on the aerodynamic characteristics of NACA 4406 is investigated in the range of 2× 10 5 ≤ Re ≤ 2× 109. As Re increases, Cl and Cd augments and decreases, respectively, and the lift-to-drag ratio increases linearly
The Effect of an Intravitreal Triamcinolone Acetonide Injection for Acute Nonarteritic Anterior Ischemic Optic Neuropathy
The purpose of this case report is to evaluate the visual outcome of an intravitreal triamcinolone acetonide injection (IVTA) as a treatment for a patient with acute nonarteritic anterior ischemic optic neuropathy (NAION). A 65-year-old male patient with severe visual loss due to acute NAION was treated with 4 mg/0.1mL IVTA. Fundus examination and measurements of the patient's best-corrected visual acuity and visual field were performed before and after the injection at 2 weeks, 1 month, 3 months, and 6 months. The best-corrected visual acuity changed from 0.05 before the injection to 0.16 at 2 weeks, 0.3 at 1 month, and 0.4 at 3 months and at the final visit. Optic disc swelling had markedly decreased at 1 week postoperatively and disappeared at 2 weeks after the injection. The clinical course of this patient suggests that an IVTA may be effective in increasing visual acuity following an acute NAION. A large randomized controlled trial is needed to assess the efficacy of IVTA as a treatment for NAION
β-Caryophyllene attenuates dextran sulfate sodium-induced colitis in mice via modulation of gene expression associated mainly with colon inflammation
AbstractWe examined the modulatory activity of β-caryophyllene (CA) and gene expression in colitic colon tissues in a dextran sulfate sodium (DSS)-induced colitis model. Experimental colitis was induced by exposing male BALB/c mice to 5% DSS in drinking water for 7 days. CA (30 or 300mg/kg) was administered orally once a day together with DSS. CA administration attenuated the increases in the disease activity index, colon weight/length ratio, inflammation score, and myeloperoxidase activity in DSS-treated mice. Microarray analysis showed that CA administration regulated the expression in colon tissue of inflammation-related genes including those for cytokines and chemokines (Ccl2, Ccl7, Ccl11, Ifitm3, IL-1β, IL-28, Tnfrsf1b, Tnfrsf12a); acute-phase proteins (S100a8, Saa3, Hp); adhesion molecules (Cd14, Cd55, Cd68, Mmp3, Mmp10, Sema6b, Sema7a, Anax13); and signal regulatory proteins induced by DSS. CA significantly suppressed NF-κB activity, which mediates the expression of a different set of genes. These results suggest that CA attenuates DSS-induced colitis, possibly by modulating the expression of genes associated mainly with colon inflammation through inhibition of DSS-induced NF-κB activity
The Genome Sequence of 'Mycobacterium massiliense' Strain CIP 108297 Suggests the Independent Taxonomic Status of the Mycobacterium abscessus Complex at the Subspecies Level
Members of the Mycabacterium abscessus complex are rapidly growing mycobacteria that are emerging as human pathogens. The M. abscassus complex was previously composed of three species, namely M. abscessus sensu strict, 'M. massiliense', and M. bolletii', In 2011, 'M. massiliense' and 'M. bolletre' were united and reclassified as a single subspecies within M. abscessus: M. abscessus subsp. bolletii. However, the placement of 'M. massiliense' Within the boundary of M. abscessus subsp. balletii remains highly controversial with regard to clinical aspects. In this study, we revisited the taxonomic status of members of the M. abscessus complex based on comparative analysis of he whole-genome sequences of 53 strains, The genome sequence of the previous type strain of 'Mycobacterium massiliense' (CIP 108297) was determined using next-generation sequencing. The genome tree based on average nucleotide identity (AN I) values supported the differentiation of M. bolletii' and M. massiliense' at the subspecies level. The genome tree also clearly illustrated that 'M. bolletil' and 'M. massiliense' form a distinct phylogenetic clade within the radiation of the M. abscessus complex. The genomic distances observed in this study suggest that the current M. abscessus subsp. bolletii taxon should be divided into two subspecies, M. abscessus subsp. massiliense subsp. nov. and M. abscessus subsp. bolletii, to correspondingly accommodate the previously known 'M. assiliense' and 'M. bolletii' strains.
Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation
Background: Titanium dioxide (TiO2) has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25-70) together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25-70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein, Bax. Elucidating the molecular mechanisms by which nanosized particles induce activation of cell death signaling pathways would be critical for the development of prevention strategies to minimize the cytotoxicity of nanomaterials.This work was supported by the Korea Ministry of Environment and The Eco-Technopia 21 Project (091-091-081)
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