172 research outputs found

    Conserved visual capacity of rats under red light

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    Recent studies examine the behavioral capacities of rats and mice with and without visual input, and the neuronal mechanisms underlying such capacities. These animals are assumed to be functionally blind under red light, an assumption that might originate in the fact that they are dichromats who possess ultraviolet and green but not red cones. But the inability to see red as a color does not necessarily rule out form vision based on red light absorption. We measured Long-Evans rats’ capacity for visual form discrimination under red light of various wavelength bands. Upon viewing a black and white grating, they had to distinguish between two categories of orientation, horizontal and vertical. Psychometric curves plotting judged orientation versus angle demonstrate the conserved visual capacity of rats under red light. Investigations aiming to explore rodent physiological and behavioral functions in the absence of visual input should not assume red-light blindness

    Supralinear and Supramodal Integration of Visual and Tactile Signals in Rats: Psychophysics and Neuronal Mechanisms

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    To better understand how object recognition can be triggered independently of the sensory channel through which information is acquired, we devised a task in which rats judged the orientation of a raised, black and white grating. They learned to recognize two categories of orientation: 0° ± 45° ("horizontal") and 90° ± 45° ("vertical"). Each trial required a visual (V), a tactile (T), or a visual-tactile (VT) discrimination; VT performance was better than that predicted by optimal linear combination of V and T signals, indicating synergy between sensory channels. We examined posterior parietal cortex (PPC) and uncovered key neuronal correlates of the behavioral findings: PPC carried both graded information about object orientation and categorical information about the rat's upcoming choice; single neurons exhibited identical responses under the three modality conditions. Finally, a linear classifier of neuronal population firing replicated the behavioral findings. Taken together, these findings suggest that PPC is involved in the supramodal processing of shape. Knowledge about objects can be accessed through multiple sensory pathways. Nikbakht et al. find that rats judge object orientation by synergistically combining signals from vision and touch; posterior parietal cortex seems to be involved in the supramodal knowledge of orientation

    Development of constitutive model for precast prestressed concrete segmental columns

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    The interest of using precast segmental columns in construction of concrete bridges has significantly increased in recent years. One research area of concrete bridges is the application of Precast Prestressed Concrete Segmental (PPCS) Column in any structural analysis software or FE program code. Modeling a PPCS column, which consists of various materials with interaction between them, is complicated and time-consuming. This research attempts to formulate the stiffness matrix of PPCS columns in order to form the constitutive model in linear form to evaluate the response of the columns. A two-dimensional finite element model is presented in the finite element package ANSYS. Parametric studies are conducted by finite element models to verify the constitutive models for the PPCS column with a different number of concrete segments. Comparison between the constitutive model and the FE program results indicates that the constitutive model is accurate enough to predict the deformation of the PPCS columns

    In vivo E2F reporting reveals efficacious schedules of MEK1/2–CDK4/6 targeting and mTOR–s6 resistance mechanisms

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    Targeting cyclin-dependent kinases 4/6 (CDK4/6) represents a therapeutic option in combination with BRAF inhibitor and/or MEK inhibitor (MEKi) in melanoma; however, continuous dosing elicits toxicities in patients. Using quantitative and temporal in vivo reporting, we show that continuous MEKi with intermittent CDK4/6 inhibitor (CDK4/6i) led to more complete tumor responses versus other combination schedules. Nevertheless, some tumors acquired resistance that was associated with enhanced phosphorylation of ribosomal S6 protein. These data were supported by phospho-S6 staining of melanoma biopsies from patients treated with CDK4/6i plus targeted inhibitors. Enhanced phospho-S6 in resistant tumors provided a therapeutic window for the mTORC1/2 inhibitor AZD2014. Mechanistically, upregulation or mutation of NRAS was associated with resistance in in vivo models and patient samples, respectively, and mutant NRAS was sufficient to enhance resistance. This study utilizes an in vivo reporter model to optimize schedules and supports targeting mTORC1/2 to overcome MEKi plus CDK4/6i resistance. SIGnIFICAnCE: Mutant BRAF and NRAS melanomas acquire resistance to combined MEK and CDK4/6 inhibition via upregulation of mTOR pathway signaling. This resistance mechanism provides the preclinical basis to utilize mTORC1/2 inhibitors to improve MEKi plus CDK4/6i drug regimens

    Atezolizumab-Induced Psoriasiform Drug Eruption Successfully Treated with Ixekizumab: A Case Report and Literature Review

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    Immune-related cutaneous adverse events (ircAE) are commonly seen with immune checkpoint inhibitors such as atezolizumab. Atezolizumab-induced psoriasis has been previously reported as an ircAE, especially in patients with pre-existing psoriasis. The severity of the reaction influences treatment of the cutaneous eruption. Biologics should be considered as a treatment option for severe refractory psoriasiform eruptions even in patients with complex medical conditions like chronic infections and malignancy. This is the first reported case of successful treatment of atezolizumab-induced psoriasiform eruption with ixekizumab, a neutralizing IL17A monoclonal antibody, to the best of our knowledge. Herein, we present a 63-year-old man with a history of human immunodeficiency virus and psoriasis who presented with atezolizumab-induced psoriasiform eruption while being treated for metastatic hepatocellular carcinoma. After initiating ixekizumab, atezolizumab was restarted without cutaneous eruption

    Survival rate of prostate cancer in asian countries: A systematic review and meta-analysis

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    Background: Prostate cancer is one of the most common health issues among men, especially older men. In recent years, incidences of prostate cancer is increasing. Objective: The aim of this study was to provide a comprehensive estimate of the survival of prostate cancer in Asian countries. Methods: We searched five international databases including Medline/PubMed, Scopus, Embase, Web of Knowledge and ProQuest until June 1, 2018. The Newcastle-Ottawa Quality Assessment was used to evaluate the quality of selected papers. The review protocol was registered in PROSPERO (CRD42019117044). Results: A total of 714 titles were retrieved. Thirty-seven studies met the inclusion criteria. Based on the random-effect model one-year, five-year and ten-year survival rate of prostate cancer were 81 (95 CI 77.8�84.2), 61.9 (95 CI 59.5�64.3) and 36.2 (95 CI 9.2�63.2) respectively. Survival rates based on HDI level for five-year were 30.07, 43.43 and 70.84 percent for medium, high and very high levels, respectively. Conclusion: According to the results of our study, the prostate cancer survival rate in Asian countries is relatively lower than in Europe and North America. © 2020 The Author(s)

    The survival rate of hepatocellular carcinoma in asian countries: A systematic review and meta-analysis

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    Hepatocellular carcinoma or Liver cancer (LC) is the sixth most common cancer and the fourth cause of death worldwide in 2018. There has not been a comprehensive study on the survival rate of patients with LC in Asia yet. Therefore, the present study was conducted to evaluate the survival rate of patients with LC in Asian countries. The methodology of the present study is based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement. The researchers searched five international databases including Medline/PubMed, Scopus, Embase, Web of Knowledge and ProQuest until July 1, 2018. We also searched Google Scholar for detecting grey literature. The Newcastle-Ottawa Quality Assessment Form was used to evaluate the quality of selected papers. A total of 1425 titles were retrieved. 63 studies met the inclusion criteria. Based on the random-effect model one-year, three-year and five-year survival rate of LC were 34.8 (95 CI; 30.3-39.3), 19 (95 CI; 18.2-21.8) and 18.1 (95 CI;16.1-20.1) respectively. According to the results of our study, the LC survival rate in Asian countries is relatively lower than in Europe and North America. © 2020, Leibniz Research Centre for Working Environment and Human Factors. All rights reserved

    The production of all-female in rainbow trout (Oncorhynchus mykiss) using indirect feminization

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    The sex reversal technique in fish is widespread in many countries. The development of these techniques is desirable because rainbow trout males reach their gonad maturity earlier compared to the females. Rainbow trout alevins were treated with 17α-methyltestosterone incorporated in the diet (0.5. 1.5, 3, 6 and 10 mg/kg) for 60 days from the beginning of first feeding. Sex was determined at 180 and 680 dpf by sampling fish (n = 20) from each group and examining gross gonadal morphology under a dissecting microscope. Also sex reversal ratio and growth performance were determined in hormone-treated groups. These sex reversed functional males were reared for brood stock until they attained sexual maturity. At the end of experiment, normal rainbow trout eggs were fertilized with the sperms taken from sex reversed males for producing all-female populations. Examination of the results showed that 17α- methyltestosterone was effective in all treatment. The highest sex reversal ratio with 100% was observed in group treated with 0.5, 1.5 and 3 mg/kg 17α- methyltestosterone. The highest live weight ratios were observed in groups fed with 6, 0.5 17α-methyltestosterone and control group. Female progeny produced from the sex reversed males were 100 % in all males that sired offspring. All female trout stocks produced by this method have advantage in rainbow trout culture since the fish is not meant for direct human consumption and is used to generate brood stock, therefore, difference of growth parameters do not influence the success
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