241 research outputs found

    Strong Tracking Filter for Nonlinear Systems with Randomly Delayed Measurements and Correlated Noises

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    This paper proposes a novel strong tracking filter (STF), which is suitable for dealing with the filtering problem of nonlinear systems when the following cases occur: that is, the constructed model does not match the actual system, the measurements have the one-step random delay, and the process and measurement noises are correlated at the same epoch. Firstly, a framework of decoupling filter (DF) based on equivalent model transformation is derived. Further, according to the framework of DF, a new extended Kalman filtering (EKF) algorithm via using first-order linearization approximation is developed. Secondly, the computational process of the suboptimal fading factor is derived on the basis of the extended orthogonality principle (EOP). Thirdly, the ultimate form of the proposed STF is obtained by introducing the suboptimal fading factor into the above EKF algorithm. The proposed STF can automatically tune the suboptimal fading factor on the basis of the residuals between available and predicted measurements and further the gain matrices of the proposed STF tune online to improve the filtering performance. Finally, the effectiveness of the proposed STF has been proved through numerical simulation experiments

    Differential expression of decorin, EGFR and cyclin D1 during mammary gland carcinogenesis in TA2 mice with spontaneous breast cancer

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    <p>Abstract</p> <p>Background</p> <p>The Tientsin Albino 2 (TA2) mouse is an inbred strain originating from the Kunming strain. It has a high incidence of spontaneous breast cancer without the need for external inducers or carcinogens. Until now, the mechanism of carcinogenesis has remained unclear. In this study, we investigate differential gene expression, especially the expression of decorin, EGFR and cyclin D1, during mammary gland epithelial cell carcinogenesis in TA2 mice.</p> <p>Methods</p> <p>Gene expression profiles of spontaneous breast cancer and matched normal mammary gland tissues in TA2 mice were ascertained using an Affymetrix Mouse 430 2.0 array. Twelve mammary tissue samples from five month-old female TA2 mice (Group A), as well as 28 samples from mammary (Group B) and cancer tissues (Group C) of spontaneous breast cancer-bearing TA2 mice, were subsequently used to detect the expression of decorin, EGFR and cyclin D1 by real-time PCR and immunohistochemical methods.</p> <p>Results</p> <p>Several imprinted genes, oncogenes and tumor suppressor genes were differentially expressed between normal mammary gland tissues and breast cancer tissues of TA2 mice. The imprinted gene decorin and the oncogene EGFR were down-regulated in tumor tissues, while the oncogene cyclin D1 was up-regulated. Immunohistochemistry showed that samples in Group A showed high decorin expression more frequently than those in Group B (<it>P </it>< 0.05). More tissue samples in Group B than Group A were positive for nuclear EGFR, and tissue samples in Group B more frequently showed high nuclear EGFR expression than those in Group A or Group C (<it>P </it>< 0.05). The labeling index for cyclin D1 in Group C was significantly higher than in Group B. Mammary tissues of Group A expressed the highest level of decorin mRNA (<it>P </it>< 0.05), and mammary tissues of Group B expressed the highest level of EGFR mRNA (<it>P </it>< 0.05), while cancer tissues expressed the highest level of cyclin D1 mRNA (<it>P </it>< 0.05).</p> <p>Conclusions</p> <p>The expression of decorin, EGFR and cyclin D1 in mammary epithelial cells changes with increasing age. The abnormal expression of them may partly contribute to the genesis of spontaneous breast cancer in TA2 mice.</p

    Ursolic Acid Inhibits Proliferation and Induces Apoptosis of Cancer Cells In Vitro and In Vivo

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    The aims of the study are to explore the effect of ursolic acid (UA) on the growth of gastric cancer cell line BGC-803 and hepatocellular cancer cell H22 xenograft and to understand the mechanism. UA inhibits growth of BGC-803 cells in vitro in dose-dependent and time-dependent manner. Treated with UA in vivo, tumor cells can be arrested to G0/G1 stage. The apoptotic rate was significantly increased in tumor cells treated with UA both in vitro and in vivo. DNA fragmentation was found in BGC-803 cells exposed to UA. UA activated caspase-3, -8, and -9 and down regulated expression of Bcl-2 in BGC-803 cells. The expression of caspase-3 and -8 was elevated in tumor cells from xenograft treated with UA. 18F-FLT PET-CT imaging confirmed tumor model and UA effectiveness. Our results indicated that UA inhibits growth of tumor cells both in vitro and in vivo by decreasing proliferation of cells and inducing apoptosis

    Two Novel AGXT Mutations Cause the Infantile Form of Primary Hyperoxaluria Type I in a Chinese Family: Research on Missed Mutation

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    Primary hyperoxaluria type 1 (PH1) is a rare metabolic disorder characterized by a defect in the liver-specific peroxisomal enzyme alanine-glyoxylate and serine-pyruvate aminotransferase (AGT). This disorder results in hyperoxaluria, recurrent urolithiasis, and nephrocalcinosis. Three forms of PH1 have been reported. Data on the infantile form of PH1 are currently limited in literature. Despite the fact that China is the most populated country in the world, only a few AGXT mutations have been reported in several Chinese PH1 patients. In the present study, we investigated a Chinese family in which two siblings are affected by the infantile form of PH1. Sanger sequencing was carried out on the proband, but the results were misleading. Two novel missense mutations (c.517T &gt; C/p.Cys173Arg and c.667A &gt; C/p.Ser223Arg) of the AGXT gene were successfully detected through whole-exome sequencing. These two mutations occurred in the highly conserved residues of the AGT. Four software programs predicted both mutations as the cause of the disease. A postmortem examination was performed and revealed the occurrence of global nephrocalcinosis on both kidneys. The crystals were collected and analyzed as calcium oxalate monohydrate. This study extends the knowledge on the clinical phenotype–genotype correlation of the AGXT mutation. That is, (i) two novel missense mutations were identified for the infantile form of PH1 and (ii) the same AGXT genotype caused the same infantile form of PH1 within the family

    Inflammation-Related Cytokines of Aqueous Humor in Acute Primary Angle-Closure Eyes

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    PURPOSE. To measure levels of various inflammation-related cytokines in the aqueous humor of patients with acute primary angle-closure (APAC) and senile cataract. METHODS. Aqueous humor samples were prospectively collected from 23 eyes (12 eyes with current APAC and 11 eyes with previous APAC) of 23 APAC patients and 15 eyes of 15 cataract patients. The levels of 15 inflammation-related cytokines in the aqueous humor of APAC and cataract subjects were measured by using the multiplex bead immunoassay technique. Data on patient demographics and preoperative intraocular pressure (IOP) were also collected for correlation analysis

    Discovery and identification of potential biomarkers of pediatric Acute Lymphoblastic Leukemia

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    <p>Abstract</p> <p>Background</p> <p>Acute lymphoblastic leukemia (ALL) is a common form of cancer in children. Currently, bone marrow biopsy is used for diagnosis. Noninvasive biomarkers for the early diagnosis of pediatric ALL are urgently needed. The aim of this study was to discover potential protein biomarkers for pediatric ALL.</p> <p>Methods</p> <p>Ninety-four pediatric ALL patients and 84 controls were randomly divided into a "training" set (45 ALL patients, 34 healthy controls) and a test set (49 ALL patients, 30 healthy controls and 30 pediatric acute myeloid leukemia (AML) patients). Serum proteomic profiles were measured using surface-enhanced laser desorption/ionization-time-of-flight mass spectroscopy (SELDI-TOF-MS). A classification model was established by Biomarker Pattern Software (BPS). Candidate protein biomarkers were purified by HPLC, identified by LC-MS/MS and validated using ProteinChip immunoassays.</p> <p>Results</p> <p>A total of 7 protein peaks (9290 m/z, 7769 m/z, 15110 m/z, 7564 m/z, 4469 m/z, 8937 m/z, 8137 m/z) were found with differential expression levels in the sera of pediatric ALL patients and controls using SELDI-TOF-MS and then analyzed by BPS to construct a classification model in the "training" set. The sensitivity and specificity of the model were found to be 91.8%, and 90.0%, respectively, in the test set. Two candidate protein peaks (7769 and 9290 m/z) were found to be down-regulated in ALL patients, where these were identified as platelet factor 4 (PF4) and pro-platelet basic protein precursor (PBP). Two other candidate protein peaks (8137 and 8937 m/z) were found up-regulated in the sera of ALL patients, and these were identified as fragments of the complement component 3a (C3a).</p> <p>Conclusion</p> <p>Platelet factor (PF4), connective tissue activating peptide III (CTAP-III) and two fragments of C3a may be potential protein biomarkers of pediatric ALL and used to distinguish pediatric ALL patients from healthy controls and pediatric AML patients. Further studies with additional populations or using pre-diagnostic sera are needed to confirm the importance of these findings as diagnostic markers of pediatric ALL.</p

    Dynamic chromatin organization and regulatory interactions in human endothelial cell differentiation

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    Vascular endothelial cells are a mesoderm-derived lineage with many essential functions, including angiogenesis and coagulation. The gene-regulatory mechanisms underpinning endothelial specialization are largely unknown, as are the roles of chromatin organization in regulating endothelial cell transcription. To investigate the relationships between chromatin organization and gene expression, we induced endothelial cell differentiation from human pluripotent stem cells and performed Hi-C and RNA-sequencing assays at specific time points. Long-range intrachromosomal contacts increase over the course of differentiation, accompanied by widespread heteroeuchromatic compartment transitions that are tightly associated with transcription. Dynamic topologically associating domain boundaries strengthen and converge on an endothelial cell state, and function to regulate gene expression. Chromatin pairwise point interactions (DNA loops) increase in frequency during differentiation and are linked to the expression of genes essential to vascular biology. Chromatin dynamics guide transcription in endothelial cell development and promote the divergence of endothelial cells from cardiomyocytes
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