21 research outputs found

    EVALUATING CLINICAL MASTITIS IN DAIRY CATTLE FED MONENSIN

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    The effect of Monensin on clinical mastitis in dairy cattle was evaluated from data collected at nine geographical clinical field trials using 966 Holstein cows and heifers in the United States and Canada. At each site, a randomized complete block design was conducted. Monensin (Rumensin®) was fed at concentrations of 0, 8, 16, or 24 ppm in a total mixed ration beginning 21 days before first calving for all nine sites, up to 7 days after second calving for six sites, and 203 days after second calving for three sites. Quarter milk samples were taken and cultured to determine the causative pathogen for each mastitis case and if clinical signs were observed the disease data were grouped according to etiology and analyses conducted. Analyses were conducted for all clinical mastitis cases as well as for a breakdown of the clinical mastitis cases into microorganism group levels. A generalized linear mixed model and a linear mixed model were used to determine if there were significant differences in clinical mastitis between the non-zero concentrations of Monensin and controls. Response variables for the clinical mastitis cases that were analyzed using a generalized linear mixed model were Animal rate, Quarter rate, Observation rate, and Incident rate. An additional response variable, Average case duration, was analyzed using a linear mixed model. Inferences from the analyses indicate that Monensin does not influence the susceptibility of dairy cattle to clinical mastitis

    Functionalized large pore mesoporous silica nanoparticles for gene delivery featuring controlled release and co-delivery

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    Novel mesoporous silica nanoparticles (LPMSNs) functionalised with degradable poly(2-dimethylaminoethyl acrylate) (PDMAEA) have been developed (PDMAEA–LPMSNs) as nano-carriers for gene delivery. The unique design of PDMAEA–LPMSNs has endowed this system with multiple functions derived from both the organic and inorganic moieties. The cationic polymer unit binds to genetic molecules and undergoes a self-catalyzed hydrolysis in water to form a non-toxic anionic polymer poly(acrylic acid), allowing controlled release of siRNA in the cells. The nanopores of the LPMSNs provide a reservoir for storage and release of chloroquine to facilitate endosomal escape. The PDMAEA–LPMSN composites were characterized by elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), solid-state 13C magic-angle spinning nuclear magnetic resonance (MAS-NMR), thermogravimetric analysis (TGA), and nitrogen sorption techniques. Their siRNA delivery performance was tested in a KHOS cell line, showing promising potential for co-delivery of genes and drugs

    Quantitative Proteomics Identifies the Myb-Binding Protein p160 as a Novel Target of the von Hippel-Lindau Tumor Suppressor

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    Background: The von Hippel-Lindau (VHL) tumor suppressor gene encodes a component of a ubiquitin ligase complex, which is best understood as a negative regulator of hypoxia inducible factor (HIF). VHL ubiquitinates and degrades the a subunits of HIF, and this is proposed to suppress tumorigenesis and tumor angiogenesis. However, several lines of evidence suggest that there are unidentified substrates or targets for VHL that play important roles in tumor suppression. Methodology/Principal Findings: Employing quantitative proteomics, we developed an approach to systematically identify the substrates of ubiquitin ligases and using this method, we identified the Myb-binding protein p160 as a novel substrate of VHL. Conclusions/Significance: A major barrier to understanding the functions of ubiquitin ligases has been the difficulty in pinpointing their ubiquitination substrates. The quantitative proteomics approach we devised for the identification of VHL substrates will be widely applicable to other ubiquitin ligases

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Multifunctional large pore mesoporous silica nanoparticles as a novel gene carrier

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    Small interfering RNA (siRNA) based therapeutics for cancer treatments have gained considerable attention due to the high potency of siRNA in suppressing pathogenic gene expression [1]. Yet, there are drawbacks that limit siRNA application in vivo: the vulnerability of siRNA against nucleases and the inability of the nucleic acids molecules to diffuse across the cellular membranes. Nanovectors hold great promise for overcoming these limitations towards the development of efficient siRNA therapy. Various nanovectors such as lipids, polymers and inorganic nano-particles have been extensively studied. Among these nanovectors, mesoporous silica nanoparticles (MSN) show promising potential as the next-generation gene delivery carriers

    Increased activated regulatory T cells proportion correlate with the severity of idiopathic pulmonary fibrosis

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    Abstract Background Regulatory T cells (Tregs) are crucial in maintaining immune tolerance and immune homeostasis, but their role in idiopathic pulmonary fibrosis (IPF) is unclear. This study was designed to explore the role of Tregs in IPF. Methods Percentages of Tregs and their subpopulations in peripheral blood (PB) and bronchoalveolar lavage (BAL) samples were determined by flow cytometry in 29 patients with IPF, 19 patients with primary Sjögren’s syndrome-related interstitial pneumonia (pSS-IP), and 23 healthy controls (HCs). Results In peripheral blood, no difference was found in CD4+CD25+Foxp3+ Treg percentages among patients with IPF, pSS-IP, or HCs. However, activated Treg (aTreg) fractions among CD4+ T cells increased significantly in IPF compared with pSS-IP or HCs. Being consistent with the result from the PB, aTreg fractions among CD4+ T cells in IPF also increased significantly compared with pSS-IP or HCs, accompanied by increased fraction III compared with HCs in BAL. IPF patients had lower levels of resting Tregs (rTregs) from the thymus than did HCs, whereas aTreg levels originating from the thymus did not significantly differ from HCs. Both rTregs and aTregs proliferated in IPF, with aTregs being more proliferative than rTregs. Both rTregs and aTregs significantly inhibited proliferation of CD4+ T lymphocytes in vitro. The percentage of aTregs was correlated negatively with predicted diffusing capacity values for carbon monoxide and positively with GAP index in IPF. Conclusions Our study showed the imbalance between subpopulations of Tregs in IPF. Increased aTregs proportion in the peripheral blood correlated inversely with disease severity

    Serum concentrations of Krebs von den Lungen-6, surfactant protein D, and matrix metalloproteinase-2 as diagnostic biomarkers in patients with asbestosis and silicosis: a case–control study

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    Abstract Background Asbestosis and silicosis are progressive pneumoconioses characterized by interstitial fibrosis following exposure to asbestos or silica dust. We evaluated the potential diagnostic biomarkers for these diseases. Methods The serum concentrations of Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D), and matrix metalloproteinase-2 (MMP-2), MMP-7, and MMP-9 were measured in 43 patients with asbestosis, 45 patients with silicosis, 40 dust-exposed workers (DEWs) without pneumoconiosis, and 45 healthy controls (HCs). Chest high-resolution computed tomography (HRCT) images were reviewed by experts blinded to the clinical data. According to the receiver operating characteristic (ROC) curve, the ideal level of each biomarker and its diagnostic sensitivity were obtained. Results The serum KL-6 and MMP-2 concentrations were highest in patients with asbestosis, particularly in comparison with those in DEWs and HCs (P<0.05). The serum SP-D concentration was significantly higher in patients with asbestosis than in patients with silicosis, DEWs, and HCs (P<0.01), whereas no significant difference was noted among patients with silicosis, DEWs, and HCs. No significant difference in the serum MMP-7 or -9 concentration was found among patients with asbestosis, patients with silicosis, DEWs, or HCs. Among patients with asbestosis, the serum KL-6 concentration was significantly correlated with the lung fibrosis scores on HRCT and negatively correlated with the forced vital capacity (FVC) % predicted and diffusing capacity of the lung for carbon monoxide (DLCO) % predicted. The serum SP-D and MMP-2 concentrations were negatively correlated with the DLCO % predicted (all P<0.05). The order of diagnostic accuracy according to the ROC curve was KL-6, SP-D, and MMP-2 in patients with asbestosis alone and in the combination of both patients with asbestosis and those with silicosis. The combination of all three biomarkers may increase the possibility of diagnosing asbestosis (sensitivity, 93%; specificity, 57%) and both asbestosis and silicosis (sensitivity, 83%; specificity, 62%). Conclusions KL-6, SP-D, and MMP-2 are available biomarkers for the adjuvant diagnosis of asbestosis and silicosis. The combination of all three biomarkers may improve the diagnostic sensitivity for asbestosis and silicosis

    Synthesis of multi-functional large pore mesoporous silica nanoparticles as gene carriers

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    The development of functional nanocarriers that can enhance the cellular delivery of a variety of nucleic acid agents is important in many biomedical applications such as siRNA therapy. We report the synthesis of large pore mesoporous silica nanoparticles (LPMSN) loaded with iron oxide and covalently modified by polyethyleneimine (denoted PEI-Fe-LPMSN) as carriers for gene delivery. The LPMSN have a particle size of similar to 200 nm and a large pore size of 11 nm. The large pore size is essential for the formation of large iron oxide nanoparticles to increase the magnetic properties and the adsorption capacity of siRNA molecules. The magnetic property facilitates the cellular uptake of nanocarriers under an external magnetic field. PEI is covalently grafted on the silica surface to enhance the nanocarriers' affinity against siRNA molecules and to improve gene silencing performance. The PEI-Fe-LPMSN delivered siRNA-PLK1 effectively into osteosarcoma cancer cells, leading to cell viability inhibition of 80%, higher compared to the 50% reduction when the same dose of siRNA was delivered by a commercial product, oligofectamine

    Multifunctional large pore mesoporous silica nanoparticles as a novel gene carrier

    No full text
    Small interfering RNA (siRNA) based therapeutics for cancer treatments have gained considerable attention due to the high potency of siRNA in suppressing pathogenic gene expression [1]. Yet, there are drawbacks that limit siRNA application in vivo: the vulnerability of siRNA against nucleases and the inability of the nucleic acids molecules to diffuse across the cellular membranes. Nanovectors hold great promise for overcoming these limitations towards the development of efficient siRNA therapy. Various nanovectors such as lipids, polymers and inorganic nano-particles have been extensively studied. Among these nanovectors, mesoporous silica nanoparticles (MSN) show promising potential as the next-generation gene delivery carriers
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