104 research outputs found

    The influence of NF-ΚB signal-transduction pathways on the murine inner ear by acoustic overstimulation

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    Nuclear factor-kappa B (NF-ΚB) comprises a family of inducible transcription factors that serve as important regulators of the host immune and inflammatory responses. The NF-ΚB signals are activated via the canonical and/or noncanonical pathways in response to diverse stimuli. The excessive action of NF-ΚB signal-transduction pathways frequently causes self-injurious phenomena such as allergic diseases, vascular disorders, and ischemia–reperfusion neuronal damage. In the inner ear, the role of NF-ΚB has not been clarified because the activated NF-ΚB signals potentially induce both cytoprotective and cytotoxic target genes after ototoxic stimulation. In the present study, we investigated the response of NF-ΚB in both the canonical and noncanonical pathways to acoustic overstimulation (117 dB/SPL/2 hr) and followed the change of inflammatory factors (inducible nitric oxide synthase [iNOS], intracellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]) in the cochlear lateral wall (CLW) and the rest of cochlea (RoC). By means of immunohistochemistry combined with confocal microscopy and reverse transcriptase–polymerase chain reaction techniques, we found the response of NF-ΚB family members (NF-ΚB1, 2, RelA, and RelB) at the transcription level. After the NF-ΚB signaling, the inflammatory factors were significantly increased in the CLW and the RoC. Additionally, at the protein level, the prominent expression of adhesion molecules (ICAM-1 and VCAM-1) was observed in the tissue around the capillaries in the stria vascularis. These results show that acoustic overstimulation causes the NF-ΚB signaling to overexpress the inflammatory factors in the inner ear, and the up-regulation of the adhesion molecules (ICAM-1 and VCAM-1) and iNOS potentially influence the hemodynamics and the cellular integrity in the stria vascularis. Β© 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62147/1/22018_ftp.pd

    Vehicle Type Recognition Combining Global and Local Features via Two-Stage Classification

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    This study proposes a new vehicle type recognition method that combines global and local features via a two-stage classification. To extract the continuous and complete global feature, an improved Canny edge detection algorithm with smooth filtering and non-maxima suppression abilities is proposed. To extract the local feature from four partitioned key patches, a set of Gabor wavelet kernels with five scales and eight orientations is introduced. Different from the single-stage classification, where all features are incorporated into one classifier simultaneously, the proposed two-stage classification strategy leverages two types of features and classifiers. In the first stage, the preliminary recognition of large vehicle or small vehicle is conducted based on the global feature via a k-nearest neighbor probability classifier. Based on the preliminary result, the specific recognition of bus, truck, van, or sedan is achieved based on the local feature via a discriminative sparse representation based classifier. We experiment with the proposed method on the public and established datasets involving various challenging cases, such as partial occlusion, poor illumination, and scale variation. Experimental results show that the proposed method outperforms existing state-of-the-art methods

    Lipid alternations in the plasma of COVID-19 patients with various clinical presentations.

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    BACKGROUND: COVID-19 is a highly infectious respiratory disease that can manifest in various clinical presentations. Although many studies have reported the lipidomic signature of COVID-19, the molecular changes in asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals remain elusive. METHODS: This study combined a comprehensive lipidomic analysis of 220 plasma samples from 166 subjects: 62 healthy controls, 16 asymptomatic infections, and 88 COVID-19 patients. We quantified 732 lipids separately in this cohort. We performed a difference analysis, validated with machine learning models, and also performed GO and KEGG pathway enrichment analysis using differential lipids from different control groups. RESULTS: We found 175 differentially expressed lipids associated with SASR-CoV-2 infection, disease severity, and viral persistence in patients with COVID-19. PC (O-20:1/20:1), PC (O-20:1/20:0), and PC (O-18:0/18:1) better distinguished asymptomatic infected individuals from normal individuals. Furthermore, some patients tested positive for SARS-CoV-2 nucleic acid by RT-PCR but did not become negative for a longer period of time (β‰₯60 days, designated here as long-term nucleic acid test positive, LTNP), whereas other patients became negative for viral nucleic acid in a shorter period of time (≀45 days, designated as short-term nucleic acid test positive, STNP). We have found that TG (14:1/14:1/18:2) and FFA (4:0) were differentially expressed in LTNP and STNP. CONCLUSION: In summary, the integration of lipid information can help us discover novel biomarkers to identify asymptomatic individuals and further deepen our understanding of the molecular pathogenesis of COVID-19

    Prioritization of control factors for heavy metals in groundwater based on a source-oriented health risk assessment model

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    Heavy metals (HMs) in groundwater seriously threaten ecological safety and human health. To facilitate the effective management of groundwater contamination, priority control factors of HMs in groundwater need to be categorized. A total of 86 groundwater samples were collected from the Huangpi district of Wuhan city, China, during the dry and wet seasons. To determine priority control factors, a source-oriented health risk assessment model was applied to compare the pollution sources and health risks of seven HMs (Cu, Pb, Zn, Cr, Ni, As, and Fe). The results showed that the groundwater had higher As and Fe contents. The sources of HM pollution during the wet period were mainly industrial and agricultural activities and natural sources. During the dry period, origins were more complex due to the addition of domestic discharges, such as sewage wastewater. Industrial activities (74.10% during the wet period), agricultural activities (53.84% during the dry period), and As were identified as the priority control factors for groundwater HMs. The results provide valuable insights for policymakers to coordinate targeted management of HM pollution in groundwater and reduce the cost of HM pollution mitigation

    Distinct miRNAs associated with various clinical presentations of SARS-CoV-2 infection.

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    MicroRNAs (miRNAs) have been shown to play important roles in viral infections, but their associations with SARS-CoV-2 infection remain poorly understood. Here, we detected 85 differentially expressed miRNAs (DE-miRNAs) from 2,336 known and 361 novel miRNAs that were identified in 233 plasma samples from 61 healthy controls and 116 patients with COVID-19 using the high-throughput sequencing and computational analysis. These DE-miRNAs were associated with SASR-CoV-2 infection, disease severity, and viral persistence in the patients with COVID-19, respectively. Gene ontology and KEGG pathway analyses of the DE-miRNAs revealed their connections to viral infections, immune responses, and lung diseases. Finally, we established a machine learning model using the DE-miRNAs between various groups for classification of COVID-19 cases with different clinical presentations. Our findings may help understand the contribution of miRNAs to the pathogenesis of COVID-19 and identify potential biomarkers and molecular targets for diagnosis and treatment of SARS-CoV-2 infection

    Fibro-Vascular Coupling in the Control of Cochlear Blood Flow

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    Transduction of sound in the cochlea is metabolically demanding. The lateral wall and hair cells are critically vulnerable to hypoxia, especially at high sound levels, and tight control over cochlear blood flow (CBF) is a physiological necessity. Yet despite the importance of CBF for hearing, consensus on what mechanisms are involved has not been obtained.We report on a local control mechanism for regulating inner ear blood flow involving fibrocyte signaling. Fibrocytes in the super-strial region are spatially distributed near pre-capillaries of the spiral ligament of the albino guinea pig cochlear lateral wall, as demonstrably shown in transmission electron microscope and confocal images. Immunohistochemical techniques reveal the inter-connected fibrocytes to be positive for Na+/K+ ATPase Ξ²1 and S100. The connected fibrocytes display more Ca(2+) signaling than other cells in the cochlear lateral wall as indicated by fluorescence of a Ca(2+) sensor, fluo-4. Elevation of Ca(2+) in fibrocytes, induced by photolytic uncaging of the divalent ion chelator o-nitrophenyl EGTA, results in propagation of a Ca(2+) signal to neighboring vascular cells and vasodilation in capillaries. Of more physiological significance, fibrocyte to vascular cell coupled signaling was found to mediate the sound stimulated increase in cochlear blood flow (CBF). Cyclooxygenase-1 (COX-1) was required for capillary dilation.The findings provide the first evidence that signaling between fibrocytes and vascular cells modulates CBF and is a key mechanism for meeting the cellular metabolic demand of increased sound activity

    Foxtail Mosaic Virus-induced Flowering Assays in Monocot Crops

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    Virus-induced flowering (VIF) exploits RNA or DNA viruses to express flowering time genes to induce flowering in plants. Such plant virus-based tools have recently attracted widespread attention for their fundamental and applied uses in flowering physiology and in accelerating breeding in dicotyledonous crops and woody fruit-trees. We now extend this technology to a monocot grass and a cereal crop. Using the Foxtail mosaic virus-based VIF system, dubbed FoMViF, we showed that expression of florigenic Flowering Locus T (FT) genes can promote early flowering and spikelet development in proso millet, a C4 grass species with potential for nutritional food and biofuel resources, and in non-vermalized C3 wheat, a major food crop worldwide. Floral and spikelet/grain induction in the two monocot plants was caused by the virally expressed untagged or FLAG-tagged FT orthologues, and the florigenic activity of rice Hd3a was more pronounced than its dicotyledonous counterparts in proso millet. The FoMViF system is easy to perform and its efficacy to induce flowering and early spikelet/grain production is high. In addition to proso millet and wheat, we envisage that FoMViF will be also applicable to many economically important monocotyledonous food and biofuel crops

    Na+/K+-ATPase Ξ±1 Identified as an Abundant Protein in the Blood-Labyrinth Barrier That Plays an Essential Role in the Barrier Integrity

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    BACKGROUND:The endothelial-blood/tissue barrier is critical for maintaining tissue homeostasis. The ear harbors a unique endothelial-blood/tissue barrier which we term "blood-labyrinth-barrier". This barrier is critical for maintaining inner ear homeostasis. Disruption of the blood-labyrinth-barrier is closely associated with a number of hearing disorders. Many proteins of the blood-brain-barrier and blood-retinal-barrier have been identified, leading to significant advances in understanding their tissue specific functions. In contrast, capillaries in the ear are small in volume and anatomically complex. This presents a challenge for protein analysis studies, which has resulted in limited knowledge of the molecular and functional components of the blood-labyrinth-barrier. In this study, we developed a novel method for isolation of the stria vascularis capillary from CBA/CaJ mouse cochlea and provided the first database of protein components in the blood-labyrinth barrier as well as evidence that the interaction of Na(+)/K(+)-ATPase Ξ±1 (ATP1A1) with protein kinase C eta (PKCΞ·) and occludin is one of the mechanisms of loud sound-induced vascular permeability increase. METHODOLOGY/PRINCIPAL FINDINGS:Using a mass-spectrometry, shotgun-proteomics approach combined with a novel "sandwich-dissociation" method, more than 600 proteins from isolated stria vascularis capillaries were identified from adult CBA/CaJ mouse cochlea. The ion transporter ATP1A1 was the most abundant protein in the blood-labyrinth barrier. Pharmacological inhibition of ATP1A1 activity resulted in hyperphosphorylation of tight junction proteins such as occludin which increased the blood-labyrinth-barrier permeability. PKCΞ· directly interacted with ATP1A1 and was an essential mediator of ATP1A1-initiated occludin phosphorylation. Moreover, this identified signaling pathway was involved in the breakdown of the blood-labyrinth-barrier resulting from loud sound trauma. CONCLUSIONS/SIGNIFICANCE:The results presented here provide a novel method for capillary isolation from the inner ear and the first database on protein components in the blood-labyrinth-barrier. Additionally, we found that ATP1A1 interaction with PKCΞ· and occludin was involved in the integrity of the blood-labyrinth-barrier
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