110 research outputs found

    Extracting and Mathematical Identifying Form of Stationary Noise in X-ray Images

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    Image noise may prevent proper diagnostic X-ray imaging. This study is aimed at developing new noise rejection methods using a mathematical model that describes the form of X-ray image noise. Stationary noise is one type of noise found in X-ray images. Stationary noise is nonstochastic and appears independent of the radiographic factors. In this paper, we verify methods for identifying stationary noise using a polynomial regression model, and extracting such noise from X-ray images obtained from a CR system. The results of this study demonstrate that stationary noise can be extracted with high precision using a particular low-pass filter frequency. We found that a regression model for greater than second-degree polynomials can be applied for roughly identifying stationary noise. However, the fitting accuracy of the regression curve is not significantly improved in terms of the amount of multiplication required when increasing the degree of the polynomial regression model

    Neural networks for action representation: a functional magnetic-resonance imaging and dynamic causal modeling study

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    Automatic mimicry is based on the tight linkage between motor and perception action representations in which internal models play a key role. Based on the anatomical connection, we hypothesized that the direct effective connectivity from the posterior superior temporal sulcus (pSTS) to the ventral premotor area (PMv) formed an inverse internal model, converting visual representation into a motor plan, and that reverse connectivity formed a forward internal model, converting the motor plan into a sensory outcome of action. To test this hypothesis, we employed dynamic causal-modeling analysis with functional magnetic-resonance imaging (fMRI). Twenty-four normal participants underwent a change-detection task involving two visually-presented balls that were either manually rotated by the investigator's right hand (“Hand”) or automatically rotated. The effective connectivity from the pSTS to the PMv was enhanced by hand observation and suppressed by execution, corresponding to the inverse model. Opposite effects were observed from the PMv to the pSTS, suggesting the forward model. Additionally, both execution and hand observation commonly enhanced the effective connectivity from the pSTS to the inferior parietal lobule (IPL), the IPL to the primary sensorimotor cortex (S/M1), the PMv to the IPL, and the PMv to the S/M1. Representation of the hand action therefore was implemented in the motor system including the S/M1. During hand observation, effective connectivity toward the pSTS was suppressed whereas that toward the PMv and S/M1 was enhanced. Thus, the action-representation network acted as a dynamic feedback-control system during action observation

    Complete Fracture-Dislocation of the Thoracolumbar Spine with No Critical Neurological Deficit : A Case Report

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    Fractures at the thoracolumbar junction are the most common spinal column fractures. Among type C fractures in the Arbeitsgemeinschaft für Osteosynthesefragen Spine Classification, cases with complete fracture-dislocations of the spinal column often result in a critical neurological deficit despite surgical treatment. We present a case of an 18-year-old man who had a complete fracture-dislocation of the T12 vertebral body and multiple injuries following high-energy trauma but no critical neurological deficits. Because of active bleeding in the left thoracic cavity, the patient underwent open reduction of the T12 vertebral body and anterior spinal fusion of the T11-L1 vertebral bodies via an anterior approach between the T9 and T10 ribs within 24 h of the accident. Four months postoperatively, the patient could ambulate independently, with a slight disturbance of light touch. At 6 months postoperatively, plain computed tomography scans showed bony union of the T12 vertebral body. We postulated two reasons for the absence of critical neurological dysfunction : (1) spontaneous spinal canal sparing because of the fracture of the right superior articular process in the L1 vertebral body and (2) fracture morphology, that is, a rotational fracture with mild to moderately strong shearing stress to the dura mater

    Serum Autotaxin Is a Useful Disease Progression Marker in Patients with Primary Biliary Cholangitis

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    Autotaxin (ATX) is a secreted enzyme metabolized by liver sinusoidal endothelial cells that has been associated with liver fibrosis. We evaluated serum ATX values in 128 treatment-naive, histologically assessed primary biliary cholangitis (PBC) patients and 80 healthy controls for comparisons of clinical parameters in a case-control study. The median ATX concentrations in controls and PBC patients of Nakanuma's stage I, II, III, and IV were 0.70, 0.80, 0.87, 1.03, and 1.70 mg/L, respectively, which increased significantly with disease stage (r = 0.53, P < 0.0001) as confirmed by Scheuer's classification (r = 0.43, P < 0.0001). ATX correlated with Wisteria floribunda agglutinin-positive Mac-2 binding protein (M2BPGi) (r = 0.51, P < 0.0001) and fibrosis index based on four factors (FIB-4) index (r = 0.51, P < 0.0001). While ALP and M2BPGi levels had decreased significantly (both P < 0.001) by 12 months of ursodeoxycholic acid treatment, ATX had not (0.95 to 0.96 mg/L) (P = 0.07). We observed in a longitudinal study that ATX increased significantly (P < 0.00001) over 18 years in an independent group of 29 patients. Patients succumbing to disease-related death showed a significantly higher ATX increase rate (0.05 mg/L/year) than did survivors (0.02 mg/L/year) (P < 0.01). ATX therefore appears useful for assessing disease stage and prognosis in PBC.ArticleSCIENTIFIC REPORTS.8:8159(2018)journal articl

    Dual-FRET imaging of IP3 and Ca2+ revealed Ca2+-induced IP3 production maintains long lasting Ca2+ oscillations in fertilized mouse eggs

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    In most species, fertilization induces Ca(2+) transients in the egg. In mammals, the Ca(2+) rises are triggered by phospholipase Czeta (PLCzeta) released from the sperm; IP3 generated by PLCzeta induces Ca(2+) release from the intracellular Ca(2+) store through IP3 receptor, termed IP3-induced Ca(2+) release. Here, we developed new fluorescent IP3 sensors (IRIS-2s) with the wider dynamic range and higher sensitivity (Kd = 0.047-1.7 muM) than that we developed previously. IRIS-2s employed green fluorescent protein and Halo-protein conjugated with the tetramethylrhodamine ligand as fluorescence resonance energy transfer (FRET) donor and acceptor, respectively. For simultaneous imaging of Ca(2+) and IP3, using IRIS-2s as the IP3 sensor, we developed a new single fluorophore Ca(2+) sensor protein, DYC3.60. With IRIS-2s and DYC3.60, we found that, right after fertilization, IP3 concentration ([IP3]) starts to increase before the onset of the first Ca(2+) wave. [IP3] stayed at the elevated level with small peaks followed after Ca(2+) spikes through Ca(2+) oscillations. We detected delays in the peak of [IP3] compared to the peak of each Ca(2+) spike, suggesting that Ca(2+)-induced regenerative IP3 production through PLC produces small [IP3] rises to maintain [IP3] over the basal level, which results in long lasting Ca(2+) oscillations in fertilized eggs

    Protocol for a multicentre, prospective observational study of elective neck dissection for clinically node-negative oral tongue squamous cell carcinoma (END-TC study)

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    Introduction: In early-stage oral tongue squamous cell carcinoma (OTSCC), elective neck dissection (END) is recommended when occult lymph node metastasis is suspected; however, there is no unanimous consensus on the risks and benefits of END in such cases. The management of clinically node-negative (cN0) OTSCC remains controversial. This study, therefore, aimed to evaluate the efficacy of END and its impact on the quality of life (QoL) of patients with cN0 OTSCC. Methods and analysis: This is a prospective, multicentre, nonrandomised observational study. The choice of whether to perform END at the same time as resection of the primary tumour is based on institutional policy and patient preference. The primary endpoint of this study is 3-year overall survival. The secondary endpoint are 3-year disease-specific survival, 3-year relapse-free survival and the impact on patient QoL. Propensity score-matching analysis will be performed to reduce selection bias. Ethics and dissemination: This study was approved by the Clinical Research Review Board of the Nagasaki University. The protocol of this study was registered at the University Hospital Medical Information Network Clinical Trials Registry. The datasets generated during the current study will be available from the corresponding author on reasonable request. The results will be disseminated internationally, through scientific and professional conferences and in peer-reviewed medical journals

    Protocol for a multicentre, prospective observational study of elective neck dissection for clinically node-negative oral tongue squamous cell carcinoma (END-TC study)

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    Introduction In early-stage oral tongue squamous cell carcinoma (OTSCC), elective neck dissection (END) is recommended when occult lymph node metastasis issuspected; however, there is no unanimous consensus on the risks and benefits of END in such cases. The management of clinically node-negative (cN0) OTSCCremains controversial. This study, therefore, aimed to evaluate the efficacy of END and its impact on the quality of life (QoL) of patients with cN0 OTSCC.Methods and analysis This is a prospective, multicentre, nonrandomised observational study. The choice of whether to perform END at the same time as resection of the primary tumour is based on institutional policy and patient preference. The primary endpoint of this study is 3-year overall survival. The secondary endpoints are3-year disease-specific survival, 3-year relapse-free survival and the impact on patient QoL. Propensity score-matching analysis will be performed to reduce selection bias.Ethics and dissemination This study was approved by the Clinical Research Review Board of the Nagasaki University. The protocol of this study was registered at the University Hospital Medical Information Network Clinical Trials Registry. The datasets generated during the current study will be available from the correspondingauthor on reasonable request. The results will be disseminated internationally, through scientific and professional conferences and in peer-reviewed medical journals

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target
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