178 research outputs found

    Prediction of Alzheimer's disease pathophysiology based on cortical thickness patterns

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    AbstractIntroductionRecent studies have shown that pathologically defined subtypes of Alzheimer's disease (AD) represent distinctive atrophy patterns and clinical characteristics. We investigated whether a cortical thickness–based clustering method can reflect such findings.MethodsA total of 77 AD subjects from the Alzheimer's Disease Neuroimaging Initiative 2 data set who underwent 3-T magnetic resonance imaging, [18F]-fluorodeoxyglucose-positron emission tomography (PET), [18F]-Florbetapir PET, and cerebrospinal fluid (CSF) tests were enrolled. After clustering based on cortical thickness, diverse imaging and biofluid biomarkers were compared between these groups.ResultsThree cortical thinning patterns were noted: medial temporal (MT; 19.5%), diffuse (55.8%), and parietal dominant (P; 24.7%) atrophy subtypes. The P subtype was the youngest and represented more glucose hypometabolism in the parietal and occipital cortices and marked amyloid-beta accumulation in most brain regions. The MT subtype revealed more glucose hypometabolism in the left hippocampus and bilateral frontal cortices and less performance in memory tests. CSF test results did not differ between the groups.DiscussionCortical thickness patterns can reflect pathophysiological and clinical changes in AD

    Low-Dose Recombinant Adeno-Associated Virus-Mediated Inhibition of Vascular Endothelial Growth Factor Can Treat Neovascular Pathologies Without Inducing Retinal Vasculitis

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    The wet form of age-related macular degeneration is characterized by neovascular pathologies that, if untreated, can result in edemas followed by rapid vision loss. Inhibition of vascular endothelial growth factor (VEGF) has been used to successfully treat neovascular pathologies of the eye. Nonetheless, some patients require frequent intravitreal injections of anti-VEGF drugs, increasing the burden and risk of complications from the procedure to affected individuals. Recombinant adeno-associated virus (rAAV)-mediated expression of anti-VEGF proteins is an attractive alternative to reduce risk and burden to patients. However, controversy remains as to the safety of prolonged VEGF inhibition in the eye. Here, we show that two out of four rAAV serotypes tested by intravitreal delivery to express the anti-VEGF drug conbercept lead to a dose-dependent vascular sheathing pathology that is characterized by immune cell infiltrates, reminiscent of vasculitis in humans. We show that this pathology is accompanied by increased expression in vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecule 1 (ICAM1), both of which promote extravasation of immune cells from the vasculature. While formation of the vascular sheathing pathology is prevented in immunodeficient Rag-1 mice that lack B and T cells, increased expression of VACM1 and ICAM1 still occurs, indicating that inhibition of VEGF function leads to expression changes in cell adhesion molecules that promote extravasation of immune cells. Importantly, a 10-fold lower dose of one of the vectors that cause a vascular sheathing pathology is still able to reduce edemas resulting from choroidal neovascularization without causing any vascular sheathing pathology and only a minimal increase in VCAM1 expression. The data suggest that treatments of neovascular eye pathologies with rAAV-mediated expression of anti VEGF drugs can be developed safely. However, viral load needs to be adjusted to the tropisms of the serotype and the expression pattern of the promoter

    Saponin Inhibits Hepatitis C Virus Propagation by Up-regulating Suppressor of Cytokine Signaling 2

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    Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 ”g/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients

    3D Cascaded U-Net with a Squeeze-and-Exicitation Block for Semantic Segmentation on Kidney and Renal Cell Carcinoma in Abdonimal Volumetric CT

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    Segmentation is a fundamental process in medical image analysis. Recently, convolutional neural networks (CNNs) has allowed for automatic segmentation; however, segmentaiton of complex organs and diseases including the kidney or renal cell carcinoma (RCC) remains a different task due to limited data and labor-intensive labeling work. The purpose of this study is to segment kideny and RCC in CT using cascaded 3D U-Net with a squeeze-and-excitation (SE) block using a cascaded method. 210 kidneys and their RCC in abdominal CT images were used as training and validation sets. The Dice similarity coefficients (DSCs) of kidney and RCC in test set were 0.963 and 0.734 respectively. The cascaded semantic segmentation can potentially reduce segmentation efforts and increase the efficiency in clinical workflow

    Combination PI3K/MEK inhibition promotes tumor apoptosis and regression in PIK3CA wild-type, KRAS mutant colorectal cancer

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    PI3K inhibition in combination with other agents has not been studied in the context of PIK3CA wild-type, KRAS mutant cancer. In a screen of phospho-kinases, PI3K inhibition of KRAS mutant colorectal cancer cells activated the MAPK pathway. Combination PI3K/MEK inhibition with NVP-BKM120 and PD-0325901 induced tumor regression in a mouse model of PIK3CA wild-type, KRAS mutant colorectal cancer, which was mediated by inhibition of mTORC1, inhibition of MCL-1, and activation of BIM. These findings implicate mitochondrial-dependent apoptotic mechanisms as determinants for the efficacy of PI3K/MEK inhibition in the treatment of PIK3CA wild-type, KRAS mutant cancer. Keywords: PI3K; MEK; KRAS; Colorectal cancer; Mouse model of cance

    Nusinersen demonstrates effectiveness in treating spinal muscular atrophy: findings from a three-year nationwide study in Korea

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    IntroductionNusinersen is the first drug approved for spinal muscular atrophy (SMA) treatment. In this study, we aimed to evaluate the long-term safety and efficacy of nusinersen, assess the therapeutic effects based on the treatment initiation timing and baseline motor function, and explore the perception of functional improvement from either parents or patients, utilizing 3-year nationwide follow-up data in South Korea.MethodsWe enrolled patients with SMA who were treated with nusinersen under the National Health Insurance coverage, with complete motor score records available and a minimum treatment duration of 6 months. To evaluate the motor function of patients, the Hammersmith Infant Neurological Examination-2 (HINE-2) was used for type 1 and the Expanded Hammersmith Functional Motor Scale (HFMSE) was used for types 2 and 3 patients. A significant improvement was defined as a HINE-2 score gain ≄5 for patients with type 1 and an HFMSE score ≄ 3 for patients with types 2 and 3 SMA. Effects of treatment timing were assessed. Patients with type 2 were further categorized based on baseline motor scores for outcome analysis. We also analyzed a second dataset from five tertiary hospitals with the information on parents/patients-reported impressions of improvement.ResultsThe study comprised 137 patients, with 21, 103, and 13 patients representing type 1, 2, and 3 SMA, respectively. At the 3-year follow-up, the analysis encompassed 7 patients with type 1, 12 patients with type 2, and none with type 3. Nearly half of all enrolled patients across SMA types (42.8, 59.2 and 46.2%, respectively) reached the 2-year follow-up for analysis. Patients with type 1 SMA exhibited gradual motor function improvement over 1-, 2-, and 3-year follow-ups (16, 9, and 7 patients, respectively). Patients with type 2 SMA demonstrated improvement over 1-, 2-, and 3-year follow-ups (96, 61 and 12 patients, respectively). Early treatment from symptom onset resulted in better outcomes for patients with type 1 and 2 SMA. In the second dataset, 90.7% of 108 patients reported subjective improvement at the 1-year follow-up.ConclusionNusinersen treatment for types 1–3 SMA is safe and effective in long-term follow-up. Early treatment initiation was a significant factor affecting long-term motor outcome

    Comparison of the outcomes between sorafenib and lenvatinib as the first-line systemic treatment for HBV-associated hepatocellular carcinoma: a propensity score matching analysis

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    In a randomized controlled trial, lenvatinib was non-inferior to sorafenib in overall survival (OS) of patients with unresectable hepatocellular carcinoma (uHCC). This study aimed to compare the effects of sorafenib and lenvatinib as first-line systemic therapy against uHCC with real-world data in chronic hepatitis B patients. This retrospective single-center study involved 132 patients with HBV-related uHCC. Propensity score matching (PSM) was used to balance the baseline characteristics, including age, sex, serum alpha-fetoprotein levels, Child–Pugh class, tumor size, and tumor stage. The primary endpoint was overall survival (OS), and the secondary endpoints included progression-free survival (PFS), time to progression (TTP), and tumor response. After PSM, the final analysis included 44 patients treated with lenvatinib and 88 with sorafenib. The OS (7.0 vs 9.2months, p = 0.070) and PFS (4.6 vs 2.4months, p = 0.134) were comparable between the two drugs. Multivariable analysis showed that lenvatinib and sorafenib were not independent prognostic factors of OS (adjusted hazard ratio = 1.41, 95% confidence interval = 0.96–2.08, p = 0.077) after adjustment for baseline alpha-fetoprotein levels, total bilirubin levels, alanine aminotransferase level, performance status, tumor stage, and tumor size. However, the lenvatinib group had a significantly prolonged TTP (5.2 vs 2.5months, p = 0.018) and a higher objective response rate (18.2% vs 4.5%, p = 0.020) and disease control rate (77.3% vs 47.7%, p = 0.001) than the sorafenib group. Our study demonstrated that lenvatinib had a comparable OS and PFS but longer TTP and better tumor response compared to sorafenib in patients with HBV-related uHCC

    The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2

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    We present and analyze observations of polarized dust emission at 850 ÎŒm toward the central 1 7 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 - 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 \ub1 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 \ub1 0.02. Additionally, the mean Alfv\ue9n Mach number is 0.35 \ub1 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical

    The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43

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    We present observations of polarized dust emission at 850 ÎŒm from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense (NH 10 22 2 ~ –1023 cm−2) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to ∌160 ± 30 ÎŒG in the main starless core and up to ∌90 ± 40 ÎŒG in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-AlfvĂ©nic. We also present a new method of data reduction for these denser but fainter objects like starless cores
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